Revised 02-01
$2.50
Planetary Axle Wheel Ends
Maintenance Manual 9K
PRC 775P
PRC 775 W3H
PRC 425Q
(with Q Plus™ Cam Brakes)
PRC 425 W3H
PRC 775P
PRC 775 W3H
Service Notes
This maintenance manual describes the correct
service and repair procedures for AxleTech
planetary axle wheel ends. The information
contained in this manual was current at time of
printing and is subject to change without notice
or liability.
You must follow your company procedures when
you service or repair equipment or components.
You must understand all procedures and
instructions before you begin to work on a unit.
Some procedures require the use of special tools
for safe and correct service. Failure to use special
tools when required can cause serious personal
injury to service personnel, as well as damage
equipment and components.
The instructions contained in this Field
Maintenance Manual are intended for use by
skilled and experienced mechanics
knowledgeable in the installation, repair and
replacement of the AxleTech product described
herein. Installation, maintenance and replacement
of such products require a high degree of skill and
experience. The consequences of improper
installation, maintenance or replacement
(including the use of inferior or substandard
components) are grave and can result in product
failure and resulting loss of control of the vehicle,
possible injury to or death of persons and/or
possible future or additional axle damage.
AxleTech does not authorize anyone other than
highly skilled and experienced individuals to
attempt to utilize the instructions contained in this
Manual for the installation, maintenance or
replacement of the product described herein, and
AxleTech shall have no liability of any kind for
damages arising out of (or in connection with)
any other use of the information contained in this
Manual.
AxleTech International uses the following
notations to warn the user of possible safety
problems and to provide information that will
prevent damage to equipment and components.
!
WARNING
A WARNING indicates a
procedure that you must
follow exactly to avoid
serious personal injury.
!
CAUTION
A CAUTION indicates a
procedure that you must
follow exactly to avoid
damaging equipment or
components. Serious
personal injury can also
occur.
This symbol indicates that
fasteners must be
tightened to a specific
torque.
NOTE:
A NOTE indicates an
operation, procedure or
instruction that is
important for proper
service. A NOTE can also
supply information that
will help to make service
quicker and easier.
How to Order
Order items from AxleTech International.
Phone orders are also accepted by calling
AxleTech International’s Customer Service Center
at 877-547-3907 or send a fax to 866-547-3987.
Table of Contents
!
Asbestos and Non-Asbestos Fibers Warnings.................................................................................1
Section 1: Exploded Views
PRC 425Q (with Q Plus™ Cam Brakes) ........................................................................................................2
PRC 425 W3H .................................................................................................................................................3
PRC 775P ........................................................................................................................................................4
PRC 775 W3H .................................................................................................................................................5
Section 2: Introduction
Description .....................................................................................................................................................6
Identification ..................................................................................................................................................7
Section 3: Disassembly
PRC 425Q (with Q Plus™ Cam Brakes) Planetary Axle
Removal – PRC 425 Q Plus™ Cam Brake Planetary Axle Wheel End .................................................8
Brake Drum
Planetary Spider Assembly...................................................................................................................10
Cam Brakes.............................................................................................................................................11
Spindle and Brake Spider
PRC 425 W3H Wet Disc Brake
Removal – PRC 425 W3H Wet Disc Brake Wheel End.........................................................................13
Preliminary Disassembly
Planetary Spider Assembly...................................................................................................................14
Wheel End ..............................................................................................................................................15
Spindle and Piston Housing
Wet Disc Brakes .....................................................................................................................................16
PRC 775P Planetary Axle
Removal – PRC 775P Planetary Axle Wheel End.................................................................................17
Brake Drum
Planetary Spider Assembly...................................................................................................................19
Cam Brakes.............................................................................................................................................20
Spindle and Brake Spider
PRC 775 W3H Wet Disc Brake
Removal – PRC 775 W3H Wet Disc Brake Wheel End........................................................................21
Preliminary Disassembly
Planetary Spider Assembly...................................................................................................................22
Wheel End ..............................................................................................................................................23
Spindle and Piston Housing
Wet Disc Brakes .....................................................................................................................................24
Table of Contents
Section 4: Prepare Parts for Assembly
Clean Ground or Polished Parts .................................................................................................................25
Clean Parts with a Rough Finish
Clean Axle Assemblies
Dry Cleaned Parts
Prevent Corrosion
Inspect Parts.................................................................................................................................................26
Inspect Tapered Roller Bearings
Inspect the Bevel Pinion and Ring Gear Sets............................................................................................27
Inspect the Main Differential Assembly.....................................................................................................28
Inspect the Axle Shafts
Inspect the Yoke
Inspect the Brakes
Repair or Replace Parts
Repair Welding
Apply Silicone Gasket Material ..................................................................................................................29
Section 5: Assembly
PRC 425Q (with Q Plus™ Cam Brakes) Planetary Axle
PRC 425Q (with Q Plus™ Cam Brakes) Planetary Axle Wheel End ..................................................30
Prepare Parts for Assembly
Assembly
Spindle, Brake Spider and Brake
Wheel End ..............................................................................................................................................31
Adjust the Wheel Bearing Preload ......................................................................................................32
Planetary Spider and Gearing Assembly
Planetary Spider Assembly ..................................................................................................................33
PRC 425 W3H Wet Disc Brake
Assembly – PRC 425 W3H Wet Disc Brake Wheel End ......................................................................34
Prepare Parts for Assembly
Spindle and Piston Housing to the Axle Housing
Wet Disc Brakes
Wheel End ..............................................................................................................................................35
Adjust the Wheel Bearing Preload ......................................................................................................36
Planetary Spider and Gearing Assembly ............................................................................................37
Planetary Spider Assembly ..................................................................................................................38
Fill Wet Disc Brakes with Hydraulic Fluid
PRC 775P Planetary Axle
Assembly – PRC 775P Planetary Axle Wheel End ..............................................................................39
Prepare Parts for Assembly
Spindle, Brake Spider and Brake
Wheel End ..............................................................................................................................................40
Adjust the Wheel Bearing Preload ......................................................................................................41
Planetary Spider and Gearing Assembly ............................................................................................42
Planetary Spider Assembly
Table of Contents
PRC 775 W3H Wet Disc Brake
Assembly – PRC 775 W3H Wet Disc Brake Wheel End ......................................................................43
Prepare Parts for Assembly
Spindle and Piston Housing to the Axle Housing
Wet Disc Brakes
Wheel End
Adjust the Wheel Bearing Preload ......................................................................................................45
Planetary Spider and Gearing Assembly ............................................................................................46
Planetary Spider Assembly
Fill Wet Disc Brakes with Hydraulic Fluid
Section 6: Specifications
PRC 425 Q Plus™ Wheel End Torque Chart ..............................................................................................48
PRC 425 W3H Wheel End Torque Chart ....................................................................................................49
PRC 775P Wheel End Torque Chart ..........................................................................................................50
PRC 775 W3H Wheel End Torque Chart ....................................................................................................51
Lubrication Specifications ..........................................................................................................................52
Lubrication Schedule
Wet Disc Brake Coolant Specifications......................................................................................................53
Sump and Forced Cooling Systems With Hub Seals
Coolant Change Intervals
Hydraulic Fluid Specifications
Notes
Asbestos and Non-Asbestos Fibers
!
ASBESTOS FIBER WARNING
!
NON-ASBESTOS FIBERS WARNING
The following procedures for servicing brakes are recommended to reduce
exposure to asbestos fiber dust, a cancer and lung disease hazard. Material
Safety Data Sheets are available from AxleTech.
The following procedures for servicing brakes are recommended to reduce
exposure to non-asbestos fiber dust, a potential cancer and lung disease
hazard. Material Safety Data Sheets are available from AxleTech.
Hazard Summary
Hazard Summary
Because some brake linings contain asbestos, workers who service brakes must
understand the potential hazards of asbestos and precautions for reducing risks. Exposure
to airborne asbestos dust can cause serious and possibly fatal diseases, including
asbestosis (a chronic lung disease) and cancer, principally lung cancer and mesothelioma
(a cancer of the lining of the chest or abdominal cavities). Some studies show that the risk
of lung cancer among persons who smoke and who are exposed to asbestos is much
greater than the risk for non-smokers. Symptoms of these diseases may not become
apparent for 15, 20 or more years after the first exposure to asbestos.
Accordingly, workers must use caution to avoid creating and breathing dust when
servicing brakes. Specific recommended work practices for reducing exposure to
asbestos dust follow. Consult your employer for more details.
Most recently manufactured brake linings do not contain asbestos fibers. These brake
linings may contain one or more of a variety of ingredients, including glass fibers, mineral
wool, aramid fibers, ceramic fibers and silica that can present health risks if inhaled.
Scientists disagree on the extent of the risks from exposure to these substances.
Nonetheless, exposure to silica dust can cause silicosis, a non-cancerous lung disease.
Silicosis gradually reduces lung capacity and efficiency and can result in serious
breathing difficulty. Some scientists believe other types of non-asbestos fibers, when
inhaled, can cause similar diseases of the lung. In addition, silica dust and ceramic fiber
dust are known to the State of California to cause lung cancer. U.S. and international
agencies have also determined that dust from mineral wool, ceramic fibers and silica are
potential causes of cancer.
Accordingly, workers must use caution to avoid creating and breathing dust when
servicing brakes. Specific recommended work practices for reducing exposure to nonasbestos dust follow. Consult your employer for more details.
Recommended Work Practices
1. Separate Work Areas. Whenever feasible, service brakes in a separate area away
from other operations to reduce risks to unprotected persons. OSHA has set a maximum
allowable level of exposure for asbestos of 0.1 f/cc as an 8-hour time-weighted average
and 1.0 f/cc averaged over a 30-minute period. Scientists disagree, however, to what
extent adherence to the maximum allowable exposure levels will eliminate the risk of
disease that can result from inhaling asbestos dust. OSHA requires that the following sign
be posted at the entrance to areas where exposures exceed either of the maximum
allowable levels:
DANGER: ASBESTOS
CANCER AND LUNG DISEASE HAZARD
AUTHORIZED PERSONNEL ONLY
RESPIRATORS AND PROTECTIVE CLOTHING
ARE REQUIRED IN THIS AREA
2. Respiratory Protection. Wear a respirator equipped with a high-efficiency (HEPA) filter
approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes,
beginning with the removal of the wheels.
3. Procedures for Servicing Brakes.
a. Enclose the brake assembly within a negative pressure enclosure. The enclosure
should be equipped with a HEPA vacuum and worker arm sleeves. With the enclosure
in place, use the HEPA vacuum to loosen and vacuum residue from the brake parts.
b. As an alternative procedure, use a catch basin with water and a biodegradable, nonphosphate, water-based detergent to wash the brake drum or rotor and other brake
parts. The solution should be applied with low pressure to prevent dust from becoming
airborne. Allow the solution to flow between the brake drum and the brake support or
the brake rotor and caliper. The wheel hub and brake assembly components should be
thoroughly wetted to suppress dust before the brake shoes or brake pads are removed.
Wipe the brake parts clean with a cloth.
c. If an enclosed vacuum system or brake washing equipment is not available, employers
may adopt their own written procedures for servicing brakes, provided that the
exposure levels associated with the employer’s procedures do not exceed the levels
associated with the enclosed vacuum system or brake washing equipment. Consult
OSHA regulations for more details.
d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use
with asbestos when grinding or machining brake linings. In addition, do such work in an
area with a local exhaust ventilation system equipped with a HEPA filter.
e. NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a
HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic
solvents, flammable solvents, or solvents that can damage brake components as
wetting agents.
4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or
by wet wiping. NEVER use compressed air or dry sweeping to clean work areas. When you
empty vacuum cleaners and handle used rags, wear a respirator equipped with a HEPA
filter approved by NIOSH or MSHA for use with asbestos. When you replace a HEPA filter,
wet the filter with a fine mist of water and dispose of the used filter with care.
5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or
smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped with
a HEPA filter to vacuum work clothes after they are worn. Launder them separately. Do not
shake or use compressed air to remove dust from work clothes.
6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with
care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations on
waste disposal.
Regulatory Guidance
References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United
States, are made to provide further guidance to employers and workers employed within
the United States. Employers and workers employed outside of the United States should
consult the regulations that apply to them for further guidance.
Recommended Work Practices
1. Separate Work Areas. Whenever feasible, service brakes in a separate area away
from other operations to reduce risks to unprotected persons.
2. Respiratory Protection. OSHA has set a maximum allowable level of exposure for
silica of 0.1 mg/m3 as an 8-hour time-weighted average. Some manufacturers of nonasbestos brake linings recommend that exposures to other ingredients found in nonasbestos brake linings be kept below 1.0 f/cc as an 8-hour time-weighted average.
Scientists disagree, however, to what extent adherence to these maximum allowable
exposure levels will eliminate the risk of disease that can result from inhaling nonasbestos dust.
Therefore, wear respiratory protection at all times during brake servicing, beginning with
the removal of the wheels. Wear a respirator equipped with a high-efficiency (HEPA)
filter approved by NIOSH or MSHA, if the exposures levels may exceed OSHA or
manufacturer’s recommended maximum levels. Even when exposures are expected to
be within the maximum allowable levels, wearing such a respirator at all times during
brake servicing will help minimize exposure.
3. Procedures for Servicing Brakes.
a. Enclose the brake assembly within a negative pressure enclosure. The enclosure
should be equipped with a HEPA vacuum and worker arm sleeves. With the
enclosure in place, use the HEPA vacuum to loosen and vacuum residue from the
brake parts.
b. As an alternative procedure, use a catch basin with water and a biodegradable, nonphosphate, water-based detergent to wash the brake drum or rotor and other brake
parts. The solution should be applied with low pressure to prevent dust from becoming
airborne. Allow the solution to flow between the brake drum and the brake support or
the brake rotor and caliper. The wheel hub and brake assembly components should be
thoroughly wetted to suppress dust before the brake shoes or brake pads are
removed. Wipe the brake parts clean with a cloth.
c. If an enclosed vacuum system or brake washing equipment is not available, carefully
clean the brake parts in the open air. Wet the parts with a solution applied with a
pump-spray bottle that creates a fine mist. Use a solution containing water, and, if
available, a biodegradable, non-phosphate, water-based detergent. The wheel hub
and brake assembly components should be thoroughly wetted to suppress dust before
the brake shoes or brake pads are removed. Wipe the brake parts clean with a cloth.
d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA when
grinding or machining brake linings. In addition, do such work in an area with a local
exhaust ventilation system equipped with a HEPA filter.
e. NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a
HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic
solvents, flammable solvents, or solvents that can damage brake components as
wetting agents.
4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter
or by wet wiping. NEVER use compressed air or dry sweeping to clean work areas.
When you empty vacuum cleaners and handle used rags, wear a respirator equipped
with a HEPA filter approved by NIOSH or MSHA, to minimize exposure. When you
replace a HEPA filter, wet the filter with a fine mist of water and dispose of the used filter
with care.
5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or
smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped
with a HEPA filter to vacuum work clothes after they are worn. Launder them separately.
Do not shake or use compressed air to remove dust from work clothes.
6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with
care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations
on waste disposal.
Regulatory Guidance
References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the
United States, are made to provide further guidance to employers and workers employed
within the United States. Employers and workers employed outside of the United States
should consult the regulations that apply to them for further guidance.
1
Section 1
Exploded View
PRC 425Q (with Q Plus™ Cam Brakes)
14
8
7
6
5
15
3
13
2
12
1
11
10
26
25
9
24
23
22
27
20
4
18
21
17
16
19
ITEM
1
2
3
4
5
6
7
8
9
2
DESCRIPTION
Brake Drum
Setscrew
Planetary Spider
Machine Screw
Pinion Shaft
Outer Thrust Washer
Planetary Pinion Gear
Inner Thrust Washer
Thrust Button
ITEM
10
11
12
13
14
15
16
17
18
DESCRIPTION
Snap Ring
Planetary Sun Gear
Thrust Washer
Planetary Ring Gear
Adjusting Nut Dowel Pin
Adjusting Nut
Outer Bearing Cone
Outer Bearing Cup
O-Ring
ITEM
DESCRIPTION
19
20
21
22
23
24
25
26
27
Wheel Nut
Hub
Wheel Stud
Inner Bearing Cup
Inner Bearing Cone
Oil Seal Assembly
Cap Screw (3/4-10 x 2.75)
Flat Washer
Spindle
Section 1
Exploded View
PRC 425 W3H
10
9
8
7
6
5
2
4
3
13
14
11
12
15
16
1
17
28
27
26
25
24
23
22
20
21
19
18
ITEM
1
2
3
4
5
6
7
8
9
10
DESCRIPTION
Magnetic Drain/Fill Plug
Setscrew
Planetary Spider
Thrust Button
Snap Ring
Planetary Sun Gear
Thrust Washer
Planetary Ring Gear
Pin
Adjusting Nut
ITEM
11
12
13
14
15
16
17
18
19
20
DESCRIPTION
Flat Washer
Capscrew
Snap Ring
Inner Thrust Washer
Planetary Pinion Gear
Outer Thrust Washer
Planetary Pinion Shaft
Outer Bearing Cone
Outer Bearing Cup
O-Ring
ITEM
21
22
23
24
25
26
27
28
DESCRIPTION
Wheel Nut
Hub
Wheel Stud
Face Seal Assembly
Inner Bearing Cup
Inner Bearing Cone
Oil Seal Assembly
Spindle
3
Section 1
Exploded View
PRC 775P
13
12
11
10
9
8
7
5
6
14
4
15
3
16
17
2
18
19
1
20
30
29
31
28
27
26
25
24
23
22
21
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
4
DESCRIPTION
Wheel Nut
Brake Drum
Magnetic Drain Fill Plug
Planetary Spider
Thrust Button
Thrust Button
Snap Ring
Planetary Sun Gear
Thrust Washer
Planetary Ring Gear
Capscrew
Lock
ITEM
13
14
15
16
17
18
19
19A
20
21
22
23
DESCRIPTION
Planetary Ring Gear Hub
Adjusting Nut
Lock Ring
Inner Thrust Washer
Planetary Pinion Gear
Outer Thrust Washer
Pinion Shaft
O-Ring (on pinion shaft)
Machine Screw
Outer Bearing Cone
Outer Bearing Cup
O-Ring
ITEM
24
25
26
27
28
29
30
31
DESCRIPTION
Hub
Wheel Stud
Inner Bearing Cup
Inner Bearing Cone
Oil Seal Assembly
Capscrew
Flat Washer
Spindle
Section 1
Exploded View
PRC 775 W3H
13
12
11
10
9
8
7
6
5
3
4
2
14
1
15
16
29
28
17
18
22
30
27
26
21
25
24
23
20
19
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
DESCRIPTION
Magnetic Drain Fill Plug
Planetary Spider
Thrust Button
Thrust Button
Snap Ring
Planetary Sun Gear
Thrust Washer
Adjusting Nut
Planetary Ring Gear
Capscrew
Lock
Planetary Ring Gear Hub
ITEM
13
14
15
16
17
18
18A
19
20
21
22
23
DESCRIPTION
O-Ring
Lock Ring
Inner Thrust Washer
Planetary Pinion Gear
Outer Thrust Washer
Pinion Shaft
O-Ring (on pinion shaft)
Outer Bearing Cone
Outer Bearing Cup
Wheel Nut
Wheel Stud
Hub
ITEM
24
25
26
27
28
29
30
DESCRIPTION
Face Seal Assembly
Inner Bearing Cup
Inner Bearing Cone
Oil Seal Assembly
Capscrew
Flat Washer
Spindle
5
Section 2
Introduction
Description
• The teeth of the floating sun gear mesh with
Meritor’s PRC 425Q (with Q Plus™ cam brakes)
and PRC 775P planetary axles incorporate a single
reduction carrier/differential assembly with
hypoid gearing. They are equipped with the
RS-145 carrier series. The final reduction is of
planetary spur designed gearing built into the
wheel hubs. The axles have only cast housings.
Figure 2.1.
• The planetary gears rotate on planetary shafts
Figure 2.1
the teeth of the planetary spur gears.
that are mounted on a spider. The planetary
gear teeth in turn mesh with the teeth of the
floating ring gear.
• The hypoid gear set in the carrier transmits
power to the axle shafts and the sun gear of
the final reduction, through the revolving
planetary gears, and into the planetary spider.
• The planetary wheel ends on both the PRC 425
and 775 are serviced almost identically for cam
or wet disc brakes.
• AxleTech does not service a carrier-mounted
park brake (if equipped).
• For the PRC 475 axle models, follow the
instructions for the PRC 775 wheel end.
PRC 425Q (with Q PLUS™ CAM BRAKES)
AxleTech planetary axles permit the hypoid
gearing of the carrier and the axle shafts to carry
only a nominal torsional load. At the same time,
they provide the highest practical numerical gear
reduction at the wheels.
• The hypoid pinion and differential assembly of
the first reduction supports the roller bearings.
• A hardened precision spacer between the inner
and outer pinion bearings adjusts and
maintains the pinion bearing preload.
• The positioning of the threaded adjusting rings
in the carrier leg and cap bores adjusts and
maintains the differential tapered bearing
preload.
6
Section 2
Introduction
Identification
The exact axle model specification is shown on
the identification tag located on the axle housing.
Figure 2.2.
Figure 2.2
SINGLE PLANETARY AXLES
R – RIGID
P – PLANETARY
ONLY IF APPLICABLE:
L – MOUNTING OTHER THAN PAD
WITH DRILLING
HOUSING TYPE
DESIGNATION:
C – INTEGRAL CAST
P R __ C 7 7 5 P 208
FIRST TWO OR THREE
DIGITS: WHEEL END
DESIGNATION
(BASIC MODEL
NUMBER)
LAST DIGIT:
CARRIER
DESIGNATION
FOR BASE MODEL
NUMBER
BRAKE TYPE:
N
P
W3H
— NONE
— CAM-MASTER® “P” SERIES CAM (Q PLUS™
IN AXLE 425)
— DURA-DISC® 14.2 in. (360 mm) WET DISC
EXACT
SPECIFICATION
7
Section 3
Disassembly
PRC 425Q (with Q Plus™ Cam Brakes) Wheel End Cross Section
OIL SEAL
INNER
BEARING
WHEEL
STUD
OUTER
BEARING
ADJUSTING
NUT
PLANETARY
GEAR
SETSCREW
PLANETARY
PINION
SHAFT
PIN
THRUST
BUTTON
SUN
GEAR
SUN GEAR
THRUST
WASHER
MAGNETIC
DRAIN PLUG
AXLE
SHAFT
!
PLANETARY
SPIDER
SPINDLE
WARNING
O-RING
BRAKE
DRUM
RING GEAR
MACHINE
SCREW
Brake Drum
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
1. Make sure the vehicle is on a level surface.
Removal
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
PRC 425Q (with Q Plus™ Cam
Brakes) Planetary Axle
Wheel End
!
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
8
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
Section 3
Disassembly
6. If necessary, remove the magnetic drain plug
from the bottom of the axle housing. Drain and
discard the lubricant from the carrier center
section.
!
Figure 3.1
WARNING
When you work on a spring chamber, carefully
follow the service instructions of the chamber
manufacturer. Sudden release of a compressed
spring can cause serious personal injury.
7. If the brake air chamber assembly has a spring
chamber unit, carefully cage and lock the
spring to prevent the spring from activating
during disassembly.
NOTE: If Meritor automatic slack adjusters are
used, refer to Maintenance Manual 4B, Automatic
Slack Adjuster for the correct adjustment
procedure. To order this publication, call
ArvinMeritor’s Customer Service Center at
800-535-5560.
10. Install capscrews into the threaded holes
in the brake drum. Gradually tighten the
capscrews in equal amounts to push
the drum off the pilot surface of the
planetary spider.
8. Adjust the brake slack adjuster to retract the
brake shoes to produce clearance between the
lining and the brake drum.
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
9. Use a lifting device to support the brake drum.
Figure 3.1.
9
Section 3
Disassembly
11. With the lifting device, carefully remove the
brake drum. Figure 3.2.
Figure 3.2
!
WARNING
Observe all warnings and cautions provided by
the press manufacturer to avoid damage to
components and serious personal injury.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
!
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
12. Remove the five slotted head machine
screws that attach the planetary spider to the
wheel hub.
Planetary Spider Assembly
• If only the planetary pinions are removed for
inspection without removing the pinion shaft,
proceed to Step 5.
!
WARNING
To avoid serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
1. With a lifting device, remove the planetary
spider from the wheel hub. Set its large
flange side on a workbench.
2. Matchmark the outer ends of the pinion
shafts and the planetary spider to aid in
reassembly if the original pinion shafts are
used.
3. Remove the setscrew from each of the
pinion shafts.
10
4. Use a press to remove the pinion shafts. If a
press is not available, use a brass drift and
mallet to drive out the shaft. Press or drive
the pinion shaft out toward the large flange
end of the planetary spider.
5. Remove the snap ring, inner thrust washer,
planetary pinion and outer thrust washer
from each pinion shaft.
6. Remove the axle shaft thrust button only if it
is worn. Press it out TOWARD the large end
of the planetary spider.
NOTE: The sun gear thrust washer may come out
with the axle shaft and sun gear assembly.
7. Remove the axle shaft, planetary sun gear
and snap ring assembly.
8. If necessary, remove the snap ring from the
axle shaft to allow for the removal of the sun
gear and sun gear thrust washer.
9. If necessary, remove the sun gear thrust
washer from the end of the planetary ring
gear.
10. Remove the planetary ring gear.
11. Remove the wheel bearing adjusting nut.
Section 3
Disassembly
!
CAUTION
The outer bearing cone will be loose as you pass
it over the end of the spindle. Hold the cone
securely to avoid dropping it and damaging
the cone.
12. Remove the wheel hub assembly. The wheel
bearings and oil seal will come off with the
wheel hub.
• If replacing the hub oil seal and bearings:
continue with Steps 13 through 16.
!
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
13. Remove the wheel hub oil seal from the
wheel hub.
14. Remove the inner bearing cone.
Spindle and Brake Spider
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting loops or lifting straps to
any shock or drop loading.
Removal of the capscrews allows the spindle and
brake assembly to separate. They can fall from
the planetary axle housing and cause damage to
components and serious personal injury.
1. To prevent the spindle and the brake spider
from falling after all the mounting capscrews
are removed, use one of the following
procedures:
15. Press out the outer bearing cup and inner
bearing cup from the hub.
A. Use a lifting device to support the spindle
during disassembly.
16. Remove and discard the O-ring from the
wheel hub.
B. Remove only two capscrews. Replace them
with two temporary M16 x 2.0 thread studs
four inches (102 mm) before the remaining
capscrews are removed. Figure 3.3.
Cam Brakes
To disassemble the PRC 425Q (with Q Plus™ cam
brakes), refer to Maintenance Manual No. 4, Cam
Brakes. To order this publication, call
ArvinMeritor’s Customer Service Center at
800-535-5560.
• Install one stud at the eleven o’clock
position.
• Install one stud at the one o’clock position.
Figure 3.3
If it is necessary to remove the anchor pins,
remove the brake dust shields for convenient
access to the anchor pins.
11
Section 3
Disassembly
2. Remove the two capscrews and washers that
mount the clamp around the brake camshaft
housing tube to the axle housing.
3. Remove the capscrews and washers that
mount the brake spider and spindle to the axle
housing.
4. Remove the brake spider and air chamber
assembly from the spindle.
5. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome the adhesion due
to the cured gasket material in the flange joint.
12
Section 3
Disassembly
PRC 425 W3H Wheel End Cross Section
INNER
BEARING
WHEEL
STUD
OUTER
BEARING
ADJUSTING
NUT
PIN
MAGNETIC
DRAIN PLUG
OIL SEAL
SUN GEAR
SUN GEAR
THRUST
WASHER
THRUST
BUTTON
AXLE SHAFT
PLANETARY
PINION SHAFT
PLANETARY
GEAR
SPINDLE
WHEEL HUB
O-RING
WET BRAKE
PISTON HOUSING
WET BRAKE
DISC HOUSING
FACE SEAL
PRC 425 W3H Wet Disc Brake
Wheel End
!
PLANETARY
SPIDER
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
Preliminary Disassembly
1. Make sure the vehicle is on a level surface.
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
6. If necessary, remove the magnetic drain plug from
the bottom of the axle housing. Drain and discard
the lubricant from the carrier center section.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
13
Section 3
Disassembly
Planetary Spider Assembly
• If only the planetary pinions are removed for
inspection without removing the pinion shaft,
proceed to Step 5.
1. With a lifting device, remove the planetary
spider from the wheel hub. Set its large flange
side on a workbench.
2. Matchmark the outer ends of the pinion shafts
and the planetary spider to aid in reassembly
if the original pinion shafts are used.
3. Remove the setscrew from each of the
pinion shafts.
!
WARNING
Observe all warnings and cautions provided by
the press manufacturer to avoid damage to
components and serious personal injury.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
!
CAUTION
8. If necessary, remove the snap ring from the
axle shaft to allow for the removal of the sun
gear and sun gear thrust washer.
9. If necessary, remove the sun gear thrust
washer from the end of the planetary ring
gear.
10. Remove the planetary ring gear.
11. Mark the position of the wheel bearing
adjusting nut. Remove the wheel bearing
adjusting nut.
!
CAUTION
The outer bearing cone will be loose as you pass
it over the end of the spindle. Hold the cone
securely to avoid dropping it and damaging
the cone.
12. Remove the outer bearing cone and wheel
hub assembly with the brake driver splines
from the friction discs. The wheel bearings
and oil seal will come off with the wheel hub.
• If replacing the hub oil seal and bearing,
continue with Steps 13 through 16.
!
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
4. Use a press to remove the pinion shafts. If a
press is not available, use a brass drift and
mallet to drive out the shaft. Press or drive the
pinion shaft out toward the large flange end of
the planetary spider.
13. Remove the wheel hub oil seal from the
wheel hub.
5. Remove the snap ring, inner thrust washer,
planetary pinion and outer thrust washer from
each pinion shaft.
6. Remove the axle shaft thrust button only if it is
worn. Press it out TOWARD the large end of
the planetary spider.
NOTE: The sun gear thrust washer may come out
with the axle shaft and sun gear assembly.
7. Remove the axle shaft, planetary sun gear and
snap ring assembly.
14
14. Remove the inner bearing cone.
15. If replacement of the wheel bearings is
necessary, press out the outer bearing cup
and inner bearing cup from the hub.
16. Remove and discard the O-ring from the
wheel hub.
Section 3
Disassembly
Wheel End
Refer to Maintenance Manual MM-20195, Wet Disc
Brake with Dowel Pins/Model W3H (360 mm). Call
AxleTech International’s Customer Service Center
at 877-547-3907 or send a fax to 866-547-3987.
You can also access maintenance and product
information on AxleTech’s website at
www.axletech.com.
!
CAUTION
!
CAUTION
Do not reuse a damaged friction disc or stationary
disc. Damage to components can result.
The friction discs and stationary discs are loose
inside the brake housing assembly. Reach
through the center of the brake housing and keep
the discs from falling out.
5. Support the brake housing assembly. Remove
the remaining capscrews.
The face seal comes off with the hub. Do not set
the hub down on the face seal. Damage to the
face seal can result. Remove the face seal from
the hub.
6. Remove the brake housing assembly from the
piston housing and set it on a table with the
discs facing up to prevent the discs from falling
out.
1. Remove the face seal half from the hub
assembly.
2. Remove the rest of the face seal from the brake
housing assembly.
7. Remove the four shoulder bolts from the piston
and piston housing.
!
CAUTION
The face seal comes off with the disc housing. Do
not set the disc housing on the face seal. Damage
to the face seal can result. Remove the face seal
from the wet disc brake housing.
NOTE: Place the face seals together and store in a
safe package to prevent damage.
!
WARNING
8. Remove the washers and springs from the four
shoulder bolts. Push the piston from the piston
housing. Use less than 20 psi (1.38 bar) air
pressure. Insert three adjuster screws. Evenly
turn the screws CLOCKWISE.
Spindle and Piston Housing
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
• Inspect to make sure that neither lifting strap
3. Loosen sixteen M16 x 1.5 threaded capscrews.
Hit the threaded capscrew heads with a mallet
to separate the wet disc brake housing.
Removal of the capscrews allows the spindle and
piston housing to separate. They can fall from the
planetary axle housing and cause damage to
components and serious personal injury.
4. Remove all but two capscrews at the eleven
o’clock and one o’clock positions.
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
1. To prevent the spindle and piston housing from
falling after all the mounting capscrews are
removed, perform the following procedures:
A. Use a lifting device to support the spindle
during disassembly.
15
Section 3
Disassembly
B. Remove only two capscrews. Replace them
with two temporary M20 x 2.5 thread studs
four inches (102 mm) before the remaining
capscrews are removed.
• Install one stud at the eleven o’clock
position.
• Install one stud at the one o’clock
position.
2. Remove the capscrews and washers that
secure the piston housing and spindle to the
axle housing.
3. Remove the piston housing from the spindle.
4. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome the adhesion due
to the cured gasket material in the flange joint.
Figure 3.4.
Figure 3.4
Wet Disc Brakes
Refer to Maintenance Manual MM-20195, Wet
Disc Brake with Dowel Pins/Model W3H (360 mm).
Call AxleTech International’s Customer Service
Center at 877-547-3907 or send a fax to
866-547-3987.
You can also access maintenance and product
information on AxleTech’s website at
www.axletech.com.
16
Section 3
Disassembly
PRC 775P Wheel End Cross Section
INNER
BEARING
OUTER
BEARING
O-RING
SPINDLE
ADJUSTING
NUT
PLANETARY
PINION GEAR
SUN GEAR
THRUST
BUTTON
PLANETARY
SPIDER
AXLE SHAFT
WHEEL HUB
O-RING
BRAKE DRUM
PRC 775P Planetary Axle
Wheel End
!
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
WHEEL
STUD
HUB
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
Brake Drum
1. Make sure the vehicle is on a level surface.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
17
Section 3
Disassembly
6. If necessary, remove the magnetic drain plug
from the bottom of the axle housing. Drain
and discard the lubricant from the carrier
center section.
!
Figure 3.5
WARNING
When you work on a spring chamber, carefully
follow the service instructions of the chamber
manufacturer. Sudden release of a compressed
spring can cause serious personal injury.
7. If the brake air chamber assembly has a spring
chamber unit, carefully cage and lock the
spring to prevent the spring from activating
during disassembly.
NOTE: If Meritor automatic slack adjusters are
used, refer to Maintenance Manual 4B, Automatic
Slack Adjuster, for the correct adjustment
procedure. To order this publication, call
ArvinMeritor’s Customer Service Center at
800-535-5560.
8. Adjust the brake slack adjuster to retract the
brake shoes to produce clearance between the
lining and the brake drum.
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
9. Use a lifting device to support the brake
drum. Figure 3.5.
18
10. Install capscrews into the threaded holes in
the brake drum. Gradually tighten the
capscrews in equal amounts to push the
drum off the pilot surface of the planetary
spider.
11. With the lifting device, carefully remove the
brake drum.
12. Remove the five slotted head machine
screws that attach the planetary spider to the
wheel hub.
Section 3
Disassembly
Planetary Spider Assembly
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
1. With a lifting device, remove the planetary
spider assembly from the wheel hub and set it
on a workbench. Rest the spider on its large
flange end.
2. If the planetary ring gear did not remain with
the planetary spider assembly during the
assembly’s removal, remove the ring gear
from the planetary ring gear hub.
6. Remove the planetary pinions and thrust
washers from the planetary spider.
7. If the axle shaft thrust button and/or ring gear
support thrust buttons are worn and require
replacement, place the planetary spider on
blocks with the large flange end facing
DOWN. Press them out toward the large end
of the planetary spider.
8. Remove the axle shaft, planetary sun gear
and snap ring assembly.
NOTE: The sun gear thrust washer may come out
with the axle shaft and sun gear assembly.
9. Remove the snap ring from the axle shaft to
allow for the removal of the sun gear from
the axle shaft.
10. If necessary, remove the sun gear thrust
washer from the axle shaft.
11. If necessary, remove the sun gear thrust
washer from the end of the spindle.
3. Mark the large ends of the planetary pinion
shafts and the planetary spider to aid in
reassembly if the original pinion shafts are
used.
12. Remove the two lock plate capscrews.
Remove the lock plate from the planetary
ring gear hub.
4. Place the planetary spider assembly on blocks
with the large flange end facing UP. Remove
the snap ring from each pinion shaft.
14. Remove the planetary ring gear hub. The
outer wheel bearing cone will remain on the
ring gear hub. If it is damaged, remove it
from the hub.
!
WARNING
Observe all warnings and cautions provided by
the press manufacturer to avoid damage to
components and serious personal injury.
13. Remove the wheel bearing adjusting nut.
15. Remove the wheel hub. The hub oil seal and
inner bearing assembly will remain in the hub.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
!
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
5. Use a press to remove the pinion shafts out of
the spider. If a press is not available, use a
brass drift and mallet to drive out the shaft.
Press or drive the pinion shaft out toward the
small end of the spider which faces DOWN.
19
Section 3
Disassembly
!
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
17. Remove the hub oil seal.
18. Remove the inner bearing cone.
19. If replacement of the wheel bearings is
necessary, press out the outer bearing cup
and inner bearing cup.
20. Remove and discard the O-ring from the
wheel hub.
Cam Brakes
To disassemble the P Series brake, refer to
Maintenance Manual 4, Cam Brakes. To order this
publication, call ArvinMeritor’s Customer Service
Center at 800-535-5560.
!
WARNING
Removal of the capscrews allows the spindle and
brake assembly to separate. They can fall from
the planetary axle housing and cause damage to
components and serious personal injury.
1. To prevent the spindle and brake spider from
falling after all the mounting capscrews are
removed, use one of the following procedures:
A. Use a lifting device to support the spindle
during disassembly.
B. Remove only two capscrews. Replace them
with two temporary M20 x 2.5 UNC thread
studs four inches (102 mm) long before the
remaining capscrews are removed. Figure 3.6.
Figure 3.6
If it is necessary to remove the anchor pins,
remove the brake dust shields for convenient
access to the anchor pins.
Spindle and Brake Spider
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
• Install one stud at the eleven o’clock
position.
• Install one stud at the one o’clock position.
2. Remove the two capscrews and washers that
mount the clamp around the brake camshaft
housing tube to the axle housing.
3. Remove the capscrews and washers that secure
the brake spider and spindle to the axle housing.
4. Remove the brake spider and air chamber
assembly from the spindle.
5. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome the adhesion due
to the cured gasket material in the flange joint.
20
Section 3
Disassembly
PRC 775 W3H Wheel End Cross Section
WHEEL
HUB
OIL SEAL
WHEEL
STUD
WHEEL HUB O-RING
SPINDLE
OUTER BEARING
PLANETARY GEAR
O-RING
PLANETARY
PINION SHAFT
ADJUSTING
NUT
THRUST
BUTTON
SUN GEAR
SUN GEAR
THRUST WASHER
AXLE SHAFT
LOCK
MAGNETIC
DRAIN PLUG
WET BRAKE
PISTON HOUSING
WET DISC BRAKE
HOUSING
INNER
BEARING
FACE SEAL
PRC 775 W3H Wet Disc Brake
Wheel End
!
PLANETARY
RING GEAR HUB
SPIDER
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle that is supported
only by jacks. Jacks can slip or fall over. Serious
personal injury can result.
Preliminary Disassembly
1. Make sure the vehicle is on a level surface.
3. Raise the vehicle so that the wheels of the axle
to be serviced are off the ground. Support the
vehicle with safety stands. Refer to the vehicle
maintenance manual for instructions on
raising the vehicle.
4. Remove the wheel nuts and dual tire/rim
assemblies from both wheel ends.
5. Rotate the wheel ends so the magnetic drain
plug in the planetary spider is at the bottom.
Remove the plug. Drain and discard the
lubricant from both wheel ends.
6. If necessary, remove the magnetic drain plug
from the bottom of the axle housing. Drain
and discard the lubricant from the carrier
center section.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
21
Section 3
Disassembly
Planetary Spider Assembly
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
1. With a lifting device, remove the planetary
spider assembly from the wheel hub and set it
on a workbench. Rest the spider on its large
flange end.
2. If the planetary ring gear did not remain with
the planetary spider assembly during the
assembly’s removal, remove the ring gear
from the planetary ring gear hub.
3. Mark the large ends of the planetary pinion
shafts and the planetary spider to aid in
reassembly if the original pinion shafts are
used.
4. Place the planetary spider assembly on blocks
with the large flange end facing UP. Remove
the snap ring from each pinion shaft.
!
WARNING
Observe all warnings and cautions provided by
the press manufacturer to avoid damage to
components and serious personal injury.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
!
CAUTION
To avoid damage to the pinion shaft, provide a
soft cushioned area to receive the pinion shaft
when it is removed from the spider.
5. Use a press to remove the pinion shafts out of
the spider. If a press is not available, use a
brass drift and mallet to drive out the shaft.
Press or drive the pinion shaft out toward the
small end of the spider which faces DOWN.
6. Remove the planetary pinions and thrust
washers from the planetary spider.
22
7. If the axle shaft thrust button and/or ring gear
support thrust buttons are worn and require
replacement, place the planetary spider on
blocks with the large flange end facing
DOWN. Press them out toward the large end
of the planetary spider.
8. Remove the axle shaft, planetary sun gear
and snap ring assembly.
NOTE: The sun gear thrust washer may come out
with the axle shaft and sun gear assembly.
9. Remove the snap ring from the axle shaft to
allow for the removal of the sun gear from
the axle shaft.
10. If necessary, remove the sun gear thrust
washer from the axle shaft.
11. If necessary, remove the sun gear thrust
washer from the end of the spindle.
12. Remove the two lock plate capscrews.
Remove the lock plate from the planetary
ring gear hub.
13. Remove the wheel bearing adjusting nut.
14. Remove the planetary ring gear hub. The
outer wheel bearing cone will remain on the
ring gear hub. If it is damaged, remove it
from the hub.
15. Remove the wheel hub with brake driver
splines from the friction discs. The hub oil seal
and inner bearing assembly will remain in
the hub.
• If replacing the hub oil seal and bearings,
continue with Steps 17 through 19.
!
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
17. Remove the hub oil seal.
18. Remove the inner bearing cone.
19. If replacement of the wheel bearings is
necessary, press out the outer bearing cup
and inner bearing cup.
20. Remove and discard the O-ring from the
wheel hub.
Section 3
Disassembly
Wheel End
Refer to Maintenance Manual MM-20195, Wet
Disc Brake with Dowel Pins/Model W3H (360 mm).
Call AxleTech International’s Customer Service
Center at 877-547-3907 or send a fax to
866-547-3987.
You can also access maintenance and product
information on AxleTech’s website at
www.axletech.com.
!
CAUTION
The face seal comes off with the hub. Do not set
the hub down on the face seal. Damage to the
face seal can result. Remove the face seal from
the hub.
1. Remove the face seal half from the hub
assembly.
2. Remove the rest of face seal from the brake
housing assembly.
!
CAUTION
The face seal comes off with the disc housing. Do
not set the disc housing on the face seal. Damage
to the face seal can result. Remove the face seal
from the disc housing.
NOTE: Place the face seals together and store in a
safe package to prevent damage.
!
WARNING
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
3. Loosen sixteen M16 x 1.5 threaded capscrews.
Hit the threaded capscrew heads with a mallet
to separate the wet disc brake housing.
4. Remove all but two capscrews at eleven
o’clock and one o’clock positions.
!
CAUTION
Do not reuse a damaged friction disc or stationary
disc. Damage to components can result.
The friction discs and stationary discs are loose
inside the brake housing assembly. Reach
through the center of the brake housing and keep
the discs from falling out.
5. Support the brake housing assembly. Remove
the remaining capscrews.
6. Remove the brake housing assembly from
the piston housing and set it on a table with
the discs facing up to prevent the discs from
falling out.
7. Remove the four shoulder bolts from the
piston and piston housing.
8. Remove the washers and springs from the four
shoulder bolts. Push the piston from the piston
housing. Use less than 20 psi (1.38 bar) air
pressure. Insert three adjuster screws. Evenly
turn the screws CLOCKWISE.
Spindle and Piston Housing
!
WARNING
To prevent serious personal injury and possible
damage to components, be very careful when
using lifting devices during service and
maintenance procedures.
• Inspect to make sure that neither lifting strap
is damaged.
• Do not subject lifting straps to any shock or
drop loading.
Removal of the capscrews allows the spindle and
piston housing to separate. They can fall from the
planetary axle housing and cause damage to
components and serious personal injury.
1. To prevent the spindle and piston housing from
falling after all the mounting capscrews are
removed, perform the following procedures:
A. Use a lifting device to support the spindle
during disassembly.
23
Section 3
Disassembly
B. Remove only two capscrews. Replace them
with two temporary M20 x 2.5 thread studs
four inches (102 mm) before the remaining
capscrews are removed.
• Install one stud at the eleven o’clock
position.
• Install one stud at the one o’clock
position.
2. Remove the capscrews and washers that
secure the piston housing and spindle to the
axle housing.
3. Remove the piston housing from the spindle.
4. Remove the spindle from the axle housing. If
necessary, tap lightly on the spindle to loosen
the pilot fit and to overcome the adhesion due
to the cured gasket material in the flange joint.
Figure 3.7.
Figure 3.7
Wet Disc Brakes
Refer to Maintenance Manual MM-20195, Wet
Disc Brake with Dowel Pins/Model W3H (360 mm).
Call AxleTech International’s Customer Service
Center at 877-547-3907 or send a fax to
866-547-3987.
You can also access maintenance and product
information on AxleTech’s website at
www.axletech.com.
24
Section 4
Prepare Parts for Assembly
!
WARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
Clean Ground or Polished Parts
!
WARNING
Clean Parts with a
Rough Finish
1. Use a cleaning solvent or a hot solution tank
with a weak alkaline solution to clean parts
with a rough finish.
2. Leave parts in the hot solution tank until they
are completely cleaned and heated. When the
parts are clean, remove them from the tank.
Solvent cleaners can be flammable, poisonous
and cause burns. Examples of solvent cleaners
are carbon tetrachloride, emulsion-type cleaners
and petroleum-based cleaners. To avoid serious
personal injury when you use solvent cleaners,
you must carefully follow the manufacturer’s
product instructions and these procedures:
3. Wash the parts with water until you
completely remove the alkaline solution.
•
•
•
•
• Before the axle is steam cleaned, close or put a
Wear safe eye protection.
Wear clothing that protects your skin.
Work in a well-ventilated area.
Do not use gasoline or solvents that contain
gasoline. Gasoline can explode.
• You must use hot solution tanks or alkaline
solutions correctly. Follow the manufacturer’s
instructions carefully.
!
CAUTION
• Use only solvent cleaners to clean ground or
polished metal parts. Hot solution tanks or
water and alkaline solutions will damage these
parts. Isopropyl alcohol, kerosene or diesel fuel
can be used for this purpose.
• If required, use a sharp knife to remove gasket
material from parts. Be careful not to damage
the ground or polished surfaces.
1. Use a cleaning solvent, kerosene or diesel fuel,
to clean ground or polished parts or surfaces.
NEVER USE GASOLINE.
2. Remove gasket material from parts. Take care
not to damage ground surfaces.
3. DO NOT clean ground or polished parts in a
hot solution tank, water, steam or alkaline
solution.
Clean Axle Assemblies
• A complete axle assembly can be steam
cleaned on the outside to remove dirt.
cover over all the openings in the axle
assembly. Examples of openings are the
breathers or vents in air chambers.
!
CAUTION
Dry bearings with clean paper or rags. Do not
use compressed air, which can cause abrasive
particles to contaminate the bearings. Damage
to components and reduced lining life can result.
Dry Cleaned Parts
• Immediately after cleaning, use clean paper,
rags or compressed air to dry parts.
Prevent Corrosion
NOTE: Parts must be clean and dry before you
lubricate them.
1. If you assemble the parts immediately after
you clean them: Lubricate the clean, dry parts
with grease to prevent corrosion.
2. If you store the parts after you clean them:
Apply a corrosion-preventive material to all
machined surfaces. Store the parts in a special
paper or other material that prevents
corrosion.
25
Section 4
Prepare Parts for Assembly
Inspect Parts
• It is important to carefully inspect all parts for
wear and damage before you assemble the
axle carrier.
• Replace damaged parts.
• A visible roller groove is worn in the cup or
cone inner race surfaces. You can see the
groove at the small or large diameter ends of
both parts. Figure 4.2.
Figure 4.2
Inspect Tapered Roller Bearings
Inspect the cup, cone, rollers and cage of all
tapered roller bearings in the assembly. If any of
the following conditions exist, replace the
bearing:
• The centers of the large diameter end of the
rollers are worn level with or below the
surface.
• The centers of the large diameter end of the
rollers are worn to a sharp edge. Figure 4.1.
Figure 4.1
WORN RADIUS
WORN SURFACE
26
CRACK
WEAR GROOVES
Section 4
Prepare Parts for Assembly
• Deep cracks or breaks are present in the cup,
cone inner race or roller surfaces.
• Bright wear marks are present on the outer
surface of the roller cage. Figure 4.3.
• Spalling or flaking is present on the cup and
cone inner race surfaces that touch the rollers.
Figure 4.5.
Figure 4.5
SPALLING AND
FLAKING
Figure 4.3
WEAR MARKS
• Etching and pitting is present on the rollers and
on surfaces of the cup and cone inner race that
touches the rollers. Figure 4.4.
Figure 4.4
ETCHING AND
PITTING
Inspect the Bevel Pinion and Ring
Gear Sets
!
CAUTION
The bevel drive pinions and ring gears are
machined in matched sets. When a drive pinion
or ring gear of a bevel set needs to be replaced,
both drive gear and pinion must be replaced at
the same time. A higher stress on the original
parts and early failure of the entire assembly will
result if a new part is used in combination with
parts that are older or worn.
1. Inspect the bevel drive pinions and ring gears
for wear and damage. Gears that are worn or
damaged must be replaced.
2. Verify the condition of the bearing cone seats
and spline on the pinion shaft.
27
Section 4
Prepare Parts for Assembly
Inspect the Main Differential
Assembly
1. Use a cleaning solvent, kerosene or diesel fuel,
to clean the interior of the main differential
assembly. NEVER USE GASOLINE.
2. Use the left shaft to rotate one side gear.
Replace the differential assembly if you see
any binding.
3. Observe the side gear and differential pinions
during rotation. Replace the differential
assembly if you see chipped or broken teeth,
or if there are damaged cases.
Inspect the Axle Shafts
If there is any wear or cracks at the flange, shaft
and splines, replace the axle shaft.
Repair or Replace Parts
Replace the worn or damaged parts of an axle
assembly. The following are some examples to
check for repair and possible replacement:
• Replace any fastener if corners of the head are
worn.
• Replace washers if damaged.
• Replace gaskets, oil seals or grease seals at the
time of axle repair.
• Clean parts and apply new liquid gasket
material where required when the axle is
assembled.
• Remove nicks, marks and burrs from parts
having machined or ground surfaces. Use a
fine file, India stone, emery cloth or crocus
cloth for this purpose.
• Clean and repair the threads of fasteners and
Inspect the Yoke
If there is excessive wear at the seal journal area,
replace the yoke.
Inspect the Brakes
Refer to Maintenance Manual MM-20195, Wet
Disc Brake with Dowel Pins/Model W3H
(360 mm). Call AxleTech International’s Customer
Service Center at 877-547-3907 or send a fax to
866-547-3987.
You can also access maintenance and product
information on AxleTech’s website at
www.axletech.com.
holes. Use a die or tap of the correct size or a
fine file for this purpose.
• Tighten all fasteners to the correct torque
values. Refer to chart in Section 6 for fastener
torque values.
Repair Welding
!
WARNING
Do not weld repair, heat, bend or recondition
axle components. This will reduce component
strength, void AxleTech’s warranty, and can
result in serious personal injury and damage to
components. Always replace damaged or
out-of-specification components.
Inspect the axle components. Replace if damaged
or worn. Do not weld repair or recondition.
28
Section 4
Prepare Parts for Assembly
Apply Silicone Gasket Material
AxleTech Specifications:
• ThreeBond 1216
• Loctite 5699
!
5. Assemble the components immediately to
permit the gasket material to compress evenly
between parts. Tighten the fasteners to the
required torque value for that size fastener using
an “X” torquing pattern. Refer to the Torque
Chart in Section 6.
6. Wait 20 minutes before filling the assembly with
lubricant.
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well-ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
1. Remove all the old gasket material from the
surfaces of both components.
2. Clean the surfaces where the liquid gasket
material will be applied. Remove all the oil,
grease, dirt and moisture.
3. Thoroughly dry both surfaces.
!
CAUTION
The amount of liquid gasket material applied to
component surface must not exceed 0.125 inch
(3.18 mm) diameter bead. Too much gasket
material can block lubrication passages. Damage
to components can result.
4. Apply a 0.125 inch (3.18 mm) diameter
continuous bead of silicone gasket material
around one surface. Also apply the gasket
material around the edge of all the fastener holes
on that surface. Figure 4.6.
Figure 4.6
0.125" (3.18 MM)
DIAMETER
SILICONE GASKET
MATERIAL BEAD
29
Section 5
Assembly
!
WARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
PRC 425Q (with Q Plus™ Cam
Brakes) Planetary Axle
Wheel End
Prepare Parts for Assembly
NOTE: Refer to Section 4, “Prepare Parts for
Assembly.”
Assembly
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well-ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
2. Apply a 0.125 inch (3.18 mm) diameter
continuous bead of silicone gasket material
around the flange mounting face of either the
axle housing or the spindle. Also apply the
gasket material around the edge of all the
fastener holes on that surface. Figure 5.2.
Figure 5.2
Spindle, Brake Spider and Brake
1. Install two temporary studs (M16 - 2.0 threads,
approximately four inches long) into the axle
housing flange. Install the studs at the eleven
o’clock and one o’clock positions. Figure 5.1.
Figure 5.1
GASKET
MATERIAL
3. Install the spindle onto the axle housing.
4. Install the brake spider onto the spindle.
5. Install and hand tighten some of the spindle
mounting capscrews and washers.
6. Remove the two temporary studs.
7. Install the remaining spindle mounting
capscrews and washers. Tighten all capscrews
to 200-260 lb-ft (270-350 N•m).
30
Section 5
Assembly
NOTE: Replace the camshaft bushing and grease
seals before the camshaft bracket is installed
onto the brake spider. Refer to Maintenance
Manual 4, Cam Brakes. To order this publication,
call ArvinMeritor’s Customer Service Center
at 800-535-5560.
8. Install the brake camshaft bracket with the
O-ring on the pilot onto the brake spider.
9. Install the four mounting capscrews and
washers. Tighten the capscrews to
85-115 lb-ft (115-156 N•m).
NOTE: Refer to Maintenance Manual 4, Cam
Brakes; and Maintenance Manual 4B, Automatic
Slack Adjuster, to install the brake camshaft,
anchor pin components, brake shoes, brake
springs, slack adjusters and related parts. To
order this publication, call ArvinMeritor’s
Customer Service Center at 800-535-5560.
10. Install the brake camshaft bracket clamp
around the bracket tube. Install the two
capscrews and washers that mount the
clamp to the axle housing. Tighten the
capscrews to 35-50 lb-ft (47-68 N•m).
11. Install the air chamber-to-bracket mounting
nuts. Tighten the nuts to 100-115 lb-ft
(136-156 N•m).
!
CAUTION
• Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will
result in oil leakage after assembly.
• Apply a light film of non-hardening sealant to
the hub bore surface to eliminate oil leakage
from the outer diameter of the seal.
• The hub oil seal is a “unitized” oil seal. The
rotating seal lips are internal. The rubber ribs
in the bore of the seal seat onto the spindle
journal surface for static sealing. The ribs must
not be cut or damaged to avoid an oil leak path.
4. Use the correct oil seal driver to install the
wheel hub oil seal. Press the seal into the hub
until the standout from the hub machined face
is 0.34 inch (8.64 mm). Figure 5.3.
Figure 5.3
0.34 inch
(8.64 mm)
12. Attach the chamber push rod yoke to the
slack adjuster. Tighten the yoke jam nut to
25-50 lb-ft (34-68 N•m).
13. Install the brake dust shield. Tighten the
mounting capscrews and washers to
35-50 lb-ft (47-68 N•m).
Wheel End
1. Press the new inner and outer bearing cups
into the wheel hub.
2. Position the wheel hub with the oil seal bore
facing UP.
3. Apply axle gear lubricant to the bearing
rollers and install the inner wheel bearing
cone.
NOTE: Use a Permatex coating to seal against
leaks around the hub oil seal. Leaks would result
in requiring disassembly, should leak be noted
after the final axle assembly.
5. Apply a light, uniform coating of Permatex to
the wheel hub bore.
6. Apply a light film of axle lubricant to the hub oil
seal rubber ribs in the oil seal bore.
7. Install the wheel hub, inner bearing and oil seal
assembly onto the spindle. Keep the hub
assembly aligned with the spindle.
31
Section 5
Assembly
8. Apply axle lubricant to the outer bearing cone
rollers. Install the outer bearing cone onto the
spindle.
9. Install the wheel bearing adjusting nut. The
dowel pin in the nut must face OUT.
Adjust the Wheel Bearing Preload
NOTE: To adjust the wheel bearing preload, the
bearings must be seated and the rollers in proper
alignment.
!
WARNING
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
1. Install the wheel bearing adjusting nut.
Tighten the nut to 400 lb-ft (542 N•m).
2. Rotate the hub in both directions. At the same
time, tap the hub several times with a brass or
plastic mallet.
3. Tighten the nut to 400 lb-ft (542 N•m) again.
4. Back off the nut approximately 1/4 turn to
relieve the preload produced in Step 3.
5. Tighten the nut to 200 lb-ft (271 N•m).
!
WARNING
Carefully align the adjusting nut dowel pin
within a ring gear tooth spline to avoid damage
to the pin. A damaged dowel pin will cause the
adjusting nut to back off and loosen the wheel
during vehicle operation. This can result in
serious personal injury and damage to
components.
6. Carefully align the adjusting nut dowel pin
within a ring gear tooth spline to avoid
damage to the dowel pin. Tighten the
adjusting nut to produce the proper alignment.
Do not back off the adjusting nut.
7. Install the planetary ring gear onto the spindle.
The dowel pin in the adjusting nut must be
installed in the hole in the ring gear face to
allow the ring gear to seat against the
adjusting nut.
32
8. Apply a thin layer of axle grease to the face
of the sun gear thrust washer.
9. Install the sun gear thrust washer. The
washer tangs must engage the holes in the
ring gear.
10. Install the planetary sun gear and snap ring
onto the axle shaft.
11. Install the axle shaft and sun gear assembly.
For correct installation:
• The axle shaft must make contact with the
differential side gear.
• The sun gear must make contact with the
thrust washer.
• The thrust washer tangs must be properly
installed in the ring gear hub holes.
12. Install the O-ring on the wheel hub at the
base of the flange.
Planetary Spider and
Gearing Assembly
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
1. If thrust button replacement is required, use
the procedure below. If the thrust button is not
to be changed, proceed to Step 2.
A. Apply liquid gasket material to the axle
shaft thrust button shaft before pressing it
into the spider.
B. Press the new axle shaft thrust button into
the planetary spider.
C. Apply a film of non-hardening sealant to
the spider pinion shaft bores.
Section 5
Assembly
2. Press the pinion shafts into the bores from the
inner cavity end of the spider. Press the noncoated end of the pinion shaft into the spider
until the end of the shaft is 2.085-2.080 inches
(52.96-52.83 mm) from the inside face of the
spider. Figure 5.4.
Figure 5.4
ASSEMBLE 3
SETSCREWS
AS SHOWN
0.3125"
(7.94 mm)
DIAMETER0.250 DEEP
ONE HOLE
EACH SHAFT
2.085-2.080"
(52.96-52.83 mm)
PRESS IN 3
SHAFTS TO
DIMENSION
SHOWN
3. Install a setscrew into each pinion shaft.
Tighten each setscrew to 35 lb-ft (47 N•m). For
new pinion shafts (if replaced), machine a hole
for the setscrew in each shaft.
A. Drill a 0.313 inch (8 mm) diameter hole
0.25 inch (6.4 mm) deep into the pinion
shaft.
Planetary Spider Assembly
NOTE: For correct installation, the planetary
pinions must contact both the sun gear and the
ring gear before installation.
1. Install the planetary spider and gearing
assembly onto the wheel hub.
2. Install the five slotted head machine screws
that attach the planetary spider to the wheel
hub. Hand tighten the screws. Seat the head of
each screw below the surface of the spider
flange.
3. Install the brake drum over the wheel studs
until the drum seats onto the planetary spider
flange.
4. Mount the inner and outer wheels. Install the
wheel nuts and tighten them to the vehicle
manufacturer’s specification.
NOTE: The PRC 425Q (with Q Plus™ Cam Brakes)
axle has a common oil level between the carrier
and the wheel ends. Three locations must be
filled. The vehicle must be on a level surface
when filling. Fill to the bottom of each fill
plughole. Wait and allow the oil to flow through
the axle. Check the oil level again after several
minutes and fill to the specified level if necessary.
5. Add the correct axle lubricant into each wheel
end through the fill/level hole in the planetary
spider at the horizontal position (3 or 9
o’clock).
B. Carefully pass the drill through the
0.375 inch-16 tapped hole in the planetary
spider boss.
6. Add the correct lubricant to the axle housing
bowl area.
C. Install the setscrew and tighten it to 35 lb-ft
(47 N•m).
7. Apply sealant to the threads of the fill/level
plugs.
4. Apply gear lubricant to the planetary pinion
bores and to the pinion shaft journals.
8. Install the fill/level plugs and tighten to 35 lb-ft
(47 N•m).
5. Install the outer thrust washer with the tang
engaged into the slot in the spider.
NOTE: If the original planetary pinions are used,
verify that the gear bores are smooth and free of
any surface damage.
6. Install the planetary pinion, inner thrust
washer and snap ring.
7. Apply liquid gasket material on the wheel hub
O-ring and the adjacent area.
33
Section 5
Assembly
PRC 425 W3H Wet Disc Brake
Wheel End
Prepare Parts for Assembly
NOTE: Refer to Section 4, “Prepare Parts for
Assembly.”
Spindle and Piston Housing
to the Axle Housing
1. Install two temporary studs (M20 x 2.5
threads, approximately four inches long) into
the axle housing flange. Install the studs at the
eleven o’clock and one o’clock positions.
Figure 5.5.
Figure 5.5
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
NOTE: The piston housing has TOP identified by a
raised lug.
2. Clean and inspect the spindle and piston
housing for damage. Apply a small, two
millimeter bead of Q48 (Loctite 518) near the
OD of the spindle flange, on both sides of the
spindle flange.
3. Mount the spindle and piston housing (lug on
TOP) onto the axle housing using thirteen
M20 x 2.5 thread capscrews. Tighten the
capscrews in an “X” torquing pattern to
achieve 370-480 lb-ft (500-650 N•m) bolt torque.
Install 10 mm x 60 mm long assembly studs
into the four M8 x 1.25 thread holes in the
piston cover.
Wet Disc Brakes
To assemble the PRC 425 W3H wet disc brakes,
refer to Maintenance Manual MM-20195, 360 mm
Wet Disc Brakes. To order this publication, call
AxleTech International’s Customer Service Center
at 877-547-3907 or send a fax to 866-547-3987.
NOTE: To continue assembling the PRC 425 W3H
wet disc brake wheel end, continue with the
following steps.
34
Section 5
Assembly
Wheel End
!
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
1. Clean and inspect the piston for damage,
inspect the piston grooves to ensure no
contaminants remain in the grooves.
2. Apply an oil lubricant to the “D” seals and
assemble the “D” seals into the appropriate
grooves in the piston.
!
WARNING
Take care when using Loctite to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
®
NOTE: The piston slightly sticks out of the piston
housing.
3. Apply an oil film coating on the piston housing
bores. Use “C” clamps to assemble the piston
over the assembly studs and push the piston
into the piston housing until it bottoms out.
4. Remove and store the four assembly studs.
5. Install washers and springs on the four
shoulder bolts.
6. Apply a small bead of Loctite 518 to the four
shoulder bolt threads and install the four
shoulder bolts into the piston and piston
housing. Tighten the four shoulder bolts to
22-30 lb-ft (30-40 N•m).
CAUTION
Do not reuse a damaged friction disc or
stationary disc. Damage to components can
result.
The friction discs and stationary discs are loose
inside the brake housing assembly. Reach
through the center of the brake housing and
keep the discs from falling out.
9. Line up all the friction disc splines and grooves
in a stack so that they can be assembled this
way inside the brake housing.
10. Place a friction disc inside the brake housing.
Place a stationary disc into the brake housing
while engaging all the dowels in the disc’s
slots.
11. Repeat these steps until completing the
assembly stack of discs. Realign all the friction
discs’ splines and grooves.
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
12. Apply a small, continuous two millimeter
bead of Loctite 518 onto the mounting face of
the brake housing. Carefully lift the brake
housing assembly (lug on TOP) and install it
onto the piston housing that is already
mounted on the axle.
13. Tighten sixteen M16 x 1.5 threaded capscrews
in an “X” torquing pattern to achieve
200-258 lb-ft (270-350 N•m) bolt torque.
NOTE: The brake housing has TOP identified with
a raised lug.
7. Clean and inspect the brake housing,
stationary plates and dowels for damage.
8. Place the brake housing on an assembly
bench. Assemble the eight dowels into the
slots in the brake housing.
35
Section 5
Assembly
NOTE: Use a Permatex coating to seal against
leaks around the hub oil seal. Leaks would result
in requiring disassembly, should the leak be
noted after the final axle assembly.
14. Install half of the face seal into the brake
housing by using a Caterpillar assembly tool
to properly position the O-ring and steel ring
assembly beyond the lip and into the tapered
bore in the brake housing.
15. Measure the height of the metal face above
the housing to ensure the tolerance is within
1 mm variation.
Adjust the Wheel Bearing Preload
!
WARNING
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
NOTE: To adjust the wheel bearing preload, the
bearings must be seated and the rollers in correct
alignment.
16. Clean and inspect the hub.
1. Install the wheel bearing adjusting nut.
Tighten the nut to 400 lb-ft (542 N•m).
17. Install the inner and outer bearing cups into
the hub. Install the inner bearing cone and
spindle seal into the hub. Press the spindle
seal flush with the shoulder in the hub bore.
2. Rotate the hub in both directions. At the same
time, tap the hub several times with a brass or
plastic mallet.
3. Tighten the nut to 400 lb-ft (542 N•m) again.
NOTE: Use a Permatex coating to seal against
leaks around the hub oil seal. Leaks would result
in requiring disassembly, should the leak be
noted after the final axle assembly.
18. Apply a light, uniform coating of Permatex to
the wheel hub bore.
NOTE: Use isopropyl alcohol to lubricate the
O-ring immediately before this installation.
19. Install the second half of the face seal into the
hub and cup assembly by using a Caterpillar
assembly tool to properly position the O-ring
and steel ring assembly beyond the lip and
into the tapered bore in the hub.
!
CAUTION
Do not apply lubricant to the O-ring. Damage and
leaks will result.
20. Apply a light coating of lubricant to the two
mating surfaces of the face seal’s steel rings
only. Do not allow the lubricant to contact the
O-ring. Use the same lubricant that was used
on the coolant side.
21. Install the hub with the brake driver splines
through the friction discs.
22. Install the outer bearing cone on the spindle.
Install the spindle nut on the spindle. Rotate the
hub while tightening the nut as recommended
in the wheel bearing adjustment procedure.
23. Perform the pressure test.
36
4. Back off the nut approximately 1/4 turn to
relieve the preload produced in Step 3.
5. Tighten the nut to 200 lb-ft (271 N•m).
!
WARNING
Carefully align the adjusting nut dowel pin within
a ring gear tooth spline to avoid damage to the
pin. A damaged dowel pin will cause the
adjusting nut to back off and loosen the wheel
during vehicle operation. This can result in
serious personal injury and damage to
components.
6. Carefully align the adjusting nut dowel pin
within a ring gear tooth spline to avoid
damage to the dowel pin. Tighten the
adjusting nut to produce the proper
alignment. Do not back off the adjusting nut.
7. Install the planetary ring gear onto the
spindle. The dowel pin in the adjusting nut
must be installed in the hole in the ring gear
face to allow the ring gear to seat against the
adjusting nut.
8. Apply a thin layer of axle grease to the face of
the sun gear thrust washer.
9. Install the sun gear thrust washer. The washer
tangs must engage the holes in the ring gear.
Section 5
Assembly
10. Install the planetary sun gear and snap ring
onto the axle shaft.
Figure 5.6
ASSEMBLE 3
SETSCREWS
AS SHOWN
11. Install the axle shaft and sun gear assembly.
For correct installation:
0.3125"
(7.94 mm)
DIAMETER0.250 DEEP
ONE HOLE
EACH SHAFT
• The axle shaft must make contact with the
differential side gear.
• The sun gear must make contact with the
thrust washer.
• The thrust washer tangs must be properly
installed in the ring gear hub holes.
2.085-2.080"
(52.96-52.83 mm)
PRESS IN 3
SHAFTS TO
DIMENSION
SHOWN
12. Install the O-ring on the wheel hub at the
base of the flange.
Planetary Spider and
Gearing Assembly
1. If thrust button replacement is required, use
the procedure below. If the thrust button is
not to be changed, proceed to Step 2.
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
A. Apply liquid gasket material to the axle
shaft thrust button shaft before pressing it
into the spider.
B. Press the new axle shaft thrust button into
the planetary spider.
C. Apply a film of non-hardening sealant to
the spider pinion shaft bores.
2. Press the pinion shafts into the bores from the
inner cavity end of the spider. Press the noncoated end of the pinion shaft into the spider
until the end of the shaft is 2.085-2.080 inches
(52.96-52.83 mm) from the inside face of the
spider. Figure 5.6.
3. Install a setscrew into each pinion shaft.
Tighten each setscrew to 35 lb-ft (47 N•m). For
new pinion shafts (if replaced), machine a hole
for the setscrew in each shaft.
A. Drill a 0.313 inch (8 mm) diameter hole
0.25 inch (6.4 mm) deep into the pinion
shaft.
B. Carefully pass the drill through the
0.375 inch-16 tapped hole in the planetary
spider boss.
C. Install the setscrew and tighten it to 35 lb-ft
(47 N•m).
4. Apply gear lubricant to the planetary pinion
bores and to the pinion shaft journals.
5. Install the outer thrust washer with the tang
engaged into the slot in the spider.
NOTE: If the original planetary pinions are used,
verify that the gear bores are smooth and free of
any surface damage.
6. Install the planetary pinion, inner thrust
washer and snap ring.
37
Section 5
Assembly
Planetary Spider Assembly
NOTE: For correct installation, the planetary
pinions must contact both the sun gear and the
ring gear before installation.
1. Install the planetary spider and gearing
assembly onto the wheel hub.
2. Install the five slotted head machine screws
that attach the planetary spider to the wheel
hub. Hand tighten the screws. Seat the head of
each screw below the surface of the spider
flange. Figure 5.7.
Figure 5.7
NOTE: The PRC 425 axle has a common oil level
between the carrier and the wheel ends. The wet
disc brakes must also be filled separately. Five
locations must be filled. The vehicle must be on a
level surface when filling. Fill to the bottom of
each fill plughole. Wait and allow the oil to flow
through the axle. Check the oil level again after
several minutes and fill to the specified level if
necessary.
5. Add the correct axle lubricant into each wheel
end through the fill/level hole in the planetary
spider at the horizontal position (three or nine
o’clock).
6. Add the correct lubricant to the axle housing
bowl area.
7. Apply sealant to the threads of the fill/level
plugs.
8. Install the fill/level plugs and tighten to 35 lb-ft
(47 N•m).
Fill Wet Disc Brakes with
Hydraulic Fluid
3. Install the brake drum over the wheel studs
until the drum seats onto the planetary spider
flange.
4. Mount the inner and outer wheels. Install the
wheel nuts and tighten them to the vehicle
manufacturer’s specification.
1. Fill the wet disc brakes with tractor oil universal
(TOU) fluid by using the 0.875"-14 UNF
O-ring plug near the top of the brake and a
0.875"-14 UNF O-ring plug above the three or
nine o’clock position. Fill the brakes until oil
exits the lower plug (above the three or nine
o’clock position). Install the lower plug and add
two more liters of oil through the top plug.
2. Connect the brake coolant lines and brake
actuation lines at the proper locations.
NOTE: Brake coolant inlet is connected to the
0.875"-14 UNF O-ring plug at the top position of
the brake between the mounting bolts. The brake
actuation line is connected at the 0.5625"-18 UNF
plug at either the three or nine o’clock position.
3. Thoroughly bleed all the air from the brake
actuation system.
38
Section 5
Assembly
PRC 775P Planetary Axle
Wheel End
Prepare Parts for Assembly
NOTE: Refer to Section 4, “Prepare Parts for
Assembly.”
Spindle, Brake Spider and Brake
!
WARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
1. Install two temporary studs (M20 - 2.5 threads,
approximately four inches long) into the axle
housing flange. Install the studs at the
eleven o’clock and one o’clock positions.
Figure 5.8.
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
2. Apply a 0.125 inch (3.18 mm) diameter
continuous bead of silicone gasket material
around the flange mounting face of either the
axle housing or the spindle. Also apply the
gasket material around the edge of all the
fastener holes on that surface.
3. Align the flange flats. Install the spindle onto
the axle housing. Figure 5.9.
Figure 5.9
Figure 5.8
GASKET
MATERIAL
4. Install the brake spider onto the spindle.
5. Install and hand tighten some of the spindle
mounting capscrews and washers.
6. Remove the two temporary studs.
7. Install the remaining spindle mounting
capscrews and washers. Tighten all capscrews
and washers to 370-480 lb-ft (500-650 N•m).
39
Section 5
Assembly
NOTE: Replace the camshaft bushing and grease
seals before the camshaft bracket is installed
onto the brake spider. Refer to Maintenance
Manual 4, Cam Brakes. To order this publication,
call ArvinMeritor’s Customer Service Center
at 800-535-5560.
8. Install the brake camshaft bracket with the
O-ring on the pilot onto the brake spider.
9. Install the four mounting capscrews and
washers. Tighten the capscrews to
85-115 lb-ft (115-156 N•m).
NOTE: Refer to Maintenance Manual 4, Cam
Brakes; and Maintenance Manual 4B, Automatic
Slack Adjuster, to install the brake camshaft,
anchor pin components, brake shoes, brake
springs, slack adjusters and related parts. To
order this publication, call ArvinMeritor’s
Customer Service Center at 800-535-5560.
10. Install the brake camshaft bracket clamp
around the bracket tube and install the two
capscrews and washers that mount the
clamp to the axle housing. Tighten the
capscrews to 35-50 lb-ft (47-68 N•m).
11. Install the air chamber-to-bracket mounting
nuts. Tighten the nuts to 100-115 lb-ft
(136-156 N•m).
3. Apply axle gear lubricant to the bearing
rollers and install the inner wheel bearing
cone.
!
CAUTION
• Do not damage the hub oil seal bore surface
in the wheel hub. Damage to this surface will
result in oil leakage after assembly.
• Apply a light film of non-hardening sealant to
the hub bore surface to eliminate oil leakage
from the outer diameter of the seal.
• The hub oil seal is a “unitized” oil seal. The
rotating seal lips are internal. The rubber ribs
in the bore of the seal seat onto the spindle
journal surface for static sealing. The ribs
must not be cut or damaged to avoid an oil
leak path.
4. Use the correct oil seal driver to install the
wheel hub oil seal. Press the seal into the hub
until the standout from the hub machined
face is 0.34 inch (8.64 mm). Figure 5.10.
Figure 5.10
12. Attach the push rod yoke to the slack
adjuster. Tighten the yoke jam nut to
25-50 lb-ft (34-68 N•m).
13. Install the brake dust shield. Tighten the
mounting capscrews and washers to
35-50 lb-ft (47-68 N•m).
Wheel End
!
CAUTION
Do not damage the hub oil seal bore surface in
the wheel hub. Damage to this surface will result
in oil leakage after assembly.
1. Press the new inner and outer bearing cups
into the wheel hub.
2. Position the wheel hub with the oil seal bore
facing UP.
40
0.34 inch
(8.64 mm)
Section 5
Assembly
NOTE: Use a Permatex coating to seal against
leaks around the hub oil seal. Leaks would result
in requiring disassembly, should the leak be
noted after the final axle assembly.
5. Apply a light, uniform coating of Permatex to
the wheel hub bore.
6. Apply a light film of axle lubricant to the hub
oil seal rubber ribs in the oil seal bore.
7. Install the wheel hub, inner bearing and oil
seal assembly onto the spindle. Keep the hub
assembly aligned with the spindle.
8. Apply axle lubricant to the outer bearing
cone rollers. Install the outer bearing cone
onto the planetary ring gear hub.
9. Install the ring gear hub and bearing
assembly onto the spindle.
10. Install the wheel bearing adjusting nut.
11. Adjust the wheel bearing preload. Refer to
the following procedure.
Adjust the Wheel Bearing Preload
NOTE: To adjust the wheel bearing preload, the
bearings must be properly seated and the rollers
properly aligned.
!
WARNING
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
NOTE: If you move the adjusting nut to align the
lock plate mounting holes, tighten the nut. Do not
loosen or back off the nut.
6. Install the lock plate.
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
7. Install the lock plate mounting screws. Tighten
the mounting screws to 20-30 lb-ft
(27-41 N•m).
• The new lock plate mounting screw threads
come equipped with a pre-applied locking
agent.
• If you use the original lock plate mounting
screws, apply two or three drops of Loctite
277 or equivalent to the internal threads of
the ring gear hub.
8. Apply axle grease to the inner face of the sun
gear thrust washer to help secure the washer
to the nut.
9. Install the sun gear thrust washer so that the
washer tangs must engage the slots in the
bearing adjusting nut.
10. Install the planetary sun gear and snap ring
onto the axle shaft.
11. Install the axle shaft and sun gear assembly.
For correct installation:
1. Install the wheel bearing adjusting nut.
Tighten the nut to 400 lb-ft (542 N•m).
• The axle shaft must make contact with the
2. Rotate the hub in both directions. At the same
time, tap the hub several times with a brass or
plastic mallet.
• The sun gear must make contact with the
3. Tighten the nut to 400 lb-ft (542 N•m) again.
differential side gear.
thrust washer.
• The thrust washer tangs must be properly
installed in the ring gear hub holes.
4. Back off the nut approximately 1/4 turn to
relieve the preload produced in Step 3.
5. Tighten the nut to 200 lb-ft (271 N•m).
41
Section 5
Assembly
Planetary Spider and
Gearing Assembly
NOTE: If the original planetary pinions are used,
verify that the gear bores are smooth and free of
any surface damage.
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
1. If the axle shaft thrust button and/or ring gear
thrust buttons are being replaced, apply liquid
gasket material to them before pressing into
the spider.
2. Place the planetary spider on a workbench
with the flange end facing UP. Press the new
buttons into the planetary spider.
3. Inspect the planet pinion bores for damage.
Do not reuse pinions with bore surface damage.
4. Apply gear lubricant to the planetary pinion
bores and to the pinion shaft journals and
shoulder surfaces.
5. Place the planetary spider on a workbench
with the flange end facing DOWN.
6. Carefully slide the planetary spider over the
edge of the workbench just far enough to
reach inside to place a planetary pinion and
thrust washer.
7. Install the planetary pinion and the inner and
outer thrust washers from the large end of the
planetary spider. The thrust washer tangs of
the thrust washer must engage the slots in the
planetary spider inner and outer support
bosses.
8. Replace the O-ring on each pinion shaft and
insert the pinion shafts. Hand tighten them to
the support journals. The large end of each
pinion shaft must face OUT.
9. Press the pinion shafts into the spider until
the pinion shaft inner shoulders contact the
thrust washers.
10. Apply a film of sealant to the outside pinion
shaft bores of the planetary spider.
11. Place the planetary spider on a workbench
with the flange end facing UP.
12. Install the snap rings on each pinion shaft.
13. Install the O-ring at the base of the wheel hub
flange.
14. Install the planetary ring gear onto the ring
gear hub.
Planetary Spider Assembly
NOTE: For correct installation, the planetary
pinions must contact both the sun gear and the
ring gear before installation.
1. Install the planetary spider and gearing
assembly onto the wheel hub.
2. Install the slotted head machine screws that
temporarily secure the planetary spider to the
wheel hub. Hand tighten the screws. Seat the
head of each screw below the surface of the
spider flange.
3. Install the brake drum over the wheel studs until
the drum seats onto the planetary spider flange.
4. Mount the inner and outer wheels. Install the
wheel nuts and tighten them to the vehicle
manufacturer’s specification.
NOTE: The PRC 775P axle has a common oil level
between the carrier and the wheel ends. Three
locations must be filled. The vehicle must be on a
level surface when filling. Fill to the bottom of each
fill plughole. Wait and allow the oil to flow through
the axle. Check the oil level again after a few
minutes and fill to the specified level if necessary.
5. Add the correct axle lubricant into each wheel
end through the fill/level hole in the planetary
spider at the horizontal position (three or nine
o’clock).
6. Add the correct lubricant to the axle housing
bowl area.
7. Apply sealant to the threads of the fill/level plugs.
8. Install the fill/level plugs and tighten them to
35 lb-ft (47 N•m).
42
Section 5
Assembly
PRC 775 W3H Wet Disc Brake
Wheel End
Prepare Parts for Assembly
NOTE: Refer to Section 4, “Prepare Parts for
Assembly.”
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
Spindle and Piston Housing
to the Axle Housing
NOTE: The piston housing has TOP identified by a
raised lug.
1. Install two temporary studs (M20 x 2.5 threads,
approximately four inches long) into the axle
housing flange. Install the studs at the eleven
o’clock and one o’clock positions. Figure 5.11.
2. Clean and inspect the spindle and piston
housing for damage. Apply a small, two
millimeter bead of Loctite 518 near the OD of
the spindle flange, on both sides of the spindle
flange.
Figure 5.11
3. Mount the spindle and piston housing (lug on
TOP) onto the axle housing using thirteen M20
x 2.5 thread capscrews. Tighten the capscrews
in an “X” torquing pattern to achieve
370-480 lb-ft (500-650 N•m) bolt torque. Install
10 mm x 60 mm long assembly studs into the
four M8 x 1.25 thread holes in the piston cover.
Wet Disc Brakes
To assemble the PRC 775 W3H wet disc brakes,
refer to Maintenance Manual MM-20195, 360 mm
Wet Disc Brakes. To order this publication, call
AxleTech International’s Customer Service Center
at 877-547-3907 or send a fax to 866-547-3987.
NOTE: To continue assembling the PRC 775 W3H
wet disc brake wheel end, continue with the
following steps.
Wheel End
1. Clean and inspect the piston for damage,
inspect the piston grooves to ensure no
contaminants remain in the grooves. Apply oil
lubricant to the “D” seals and assemble the
“D” seals into the appropriate grooves in
the piston.
43
Section 5
Assembly
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
NOTE: The piston slightly sticks out of the piston
housing.
2. Apply an oil film coating on the piston
housing bores. Use “C” clamps to assemble
the piston over the assembly studs and push
the piston into the piston housing until it
bottoms out.
3. Remove and store the four assembly studs.
4. Install washers and springs on the four
shoulder bolts.
5. Apply a small bead of Loctite 518 to the four
shoulder bolt threads and install the four
shoulder bolts into the piston and piston
housing. Tighten the four shoulder bolts to
22-30 lb-ft (30-40 N•m).
6. Clean and inspect the brake housing,
stationary plates and dowels for damage.
NOTE: The brake housing has TOP identified with
a raised lug.
7. Place the brake housing on an assembly
bench. Assemble the eight dowels into the
slots in the brake housing.
!
CAUTION
10. Repeat these steps until completing the
assembly stack of discs. Realign all the
friction disc splines and grooves.
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
11. Apply a small, continuous two millimeter
bead of Loctite 518 onto the mounting face of
the brake housing. Carefully lift the brake
housing assembly (lug on TOP) and install it
onto the piston housing that is already
mounted on the axle.
12. Tighten sixteen M16 x 1.5 threaded capscrews
in an “X” torquing pattern to achieve 200-258
lb-ft (270-350 N•m) bolt torque.
NOTE: Use isopropyl alcohol to lubricate O-ring
immediately before this installation.
13. Install half of the face seal into the brake
housing by using a Caterpillar assembly tool
to properly position the O-ring and steel ring
assembly beyond the lip and into the tapered
bore in the brake housing.
14. Clean and inspect the hub.
15. Install inner and outer bearing cups into the
hub. Install the inner bearing cone and
spindle seal into the hub. Press the spindle
seal flush with the shoulder in the hub bore.
Do not reuse a damaged friction disc or stationary
disc. Damage to components can result.
NOTE: Use a Permatex coating to seal against
leaks around the hub oil seal. Leaks would result
in requiring disassembly, should the leak be
noted after the final axle assembly.
The friction discs and stationary discs are loose
inside the brake housing assembly. Reach
through the center of the brake housing and keep
the discs from falling out.
16. Apply a light, uniform coating of Permatex to
the wheel hub bore.
8. Line up all the friction disc splines and
grooves in a stack so that they can be
assembled this way inside the brake housing.
9. Place a friction disc inside the brake housing.
Place a stationary disc into the brake housing
while engaging all the dowels in the disc’s
slots.
44
NOTE: Use isopropyl alcohol to lubricate O-ring
immediately before this installation.
17. Install the second half of the face seal into the
hub and cup assembly by using a Caterpillar
assembly tool to properly position the O-ring
and steel ring assembly beyond the lip and
into the tapered bore in the hub.
Section 5
Assembly
18. Measure height of metal face above housing
to ensure tolerance is within 1 mm variation.
!
CAUTION
Do not apply lubricant to the O-ring. Damage and
leaks will result.
19. Apply a light coating of lubricant to the two
mating surfaces of the face seal’s steel rings
only. Do not allow lubricant to contact the
O-ring. Use the same lubricant that was used
on the coolant side.
20. Install the hub with brake driver splines
through the friction discs.
21. Install the outer bearing cone on the ring gear
hub. Install the spindle nut on the spindle.
Rotate the hub while tightening the nut as
described in wheel bearing adjustment
procedure.
22. Perform the pressure test.
NOTE: If you move the adjusting nut to align the
lock plate mounting holes, tighten the nut. Do not
loosen or back off the nut.
6. Install the lock plate.
!
WARNING
Take care when using Loctite® to avoid serious
personal injury. Follow the manufacturer’s
instructions to prevent irritation to the eyes and
skin. If Loctite gets into your eyes, flush them
with water for 15 minutes. Have your eyes
checked by a doctor as soon as possible.
7. Install the lock plate mounting screws. Tighten
the mounting screws to 20-30 lb-ft
(27-41 N•m).
• The new lock plate mounting screw threads
come equipped with a pre-applied locking
agent.
• If you use the original lock plate mounting
Adjust the Wheel Bearing Preload
NOTE: To adjust the wheel bearing preload, the
bearings must be properly seated and the rollers
properly aligned.
!
WARNING
screws, apply two or three drops of Loctite
277 or equivalent to the internal threads of
the ring gear hub.
8. Apply axle grease to the inner face of the sun
gear thrust washer to help secure the washer
to the nut.
9. Install the sun gear thrust washer so that the
washer tangs must engage the slots in the
bearing adjusting nut.
Use a brass or leather mallet for assembly and
disassembly procedures. Do not hit steel parts
with a steel hammer. Pieces of a part can break
off and cause serious personal injury.
10. Install the planetary sun gear and snap ring
onto the axle shaft.
1. Install the wheel bearing adjusting nut. Tighten
the nut to 400 lb-ft (542 N•m).
11. Install the axle shaft and sun gear assembly.
For correct installation:
2. Rotate the hub in both directions. At the same
time, tap the hub several times with a brass or
plastic mallet.
3. Tighten the nut to 400 lb-ft (542 N•m) again.
4. Back off the nut approximately 1/4 turn to
relieve the preload produced in Step 3.
• The axle shaft must make contact with the
differential side gear.
• The sun gear must make contact with the
thrust washer.
• The thrust washer tangs must be properly
installed in the bearing adjusting nut slots.
5. Tighten the nut to 200 lb-ft (271 N•m).
45
Section 5
Assembly
Planetary Spider and
Gearing Assembly
10. Apply a film of sealant to the outside pinion
shaft bores of the planetary spider.
NOTE: If the original planetary pinions are used,
verify that the gear bores are smooth and free of
any surface damage.
12. Install the snap rings on each pinion shaft.
1. If the axle shaft thrust button and/or ring gear
thrust buttons are being replaced, apply liquid
gasket material to them before pressing into
the spider.
2. Place the planetary spider on a workbench with
the flange end facing UP. Press the new
buttons into the planetary spider.
3. Inspect the planet pinion bores for damage. Do
not reuse pinions with bore surface damage.
4. Apply gear lubricant to the planetary pinion
bores and to the pinion shaft journals and
shoulder surfaces.
5. Place the planetary spider on a workbench with
the flange end facing DOWN.
6. Carefully slide the planetary spider over the
edge of the workbench just far enough to reach
inside to place a planetary pinion and thrust
washer.
7. Install the planetary pinion and the inner and
outer thrust washers from the large end of the
planetary spider. The thrust washer tangs of
the thrust washer must engage the slots in the
planetary spider inner and outer support
bosses.
8. Replace the O-ring on each pinion shaft and
insert the pinion shafts. Hand tighten them to
the support journals. The large end of each
pinion shaft must face OUT.
9. Press the pinion shafts into the spider until the
pinion shaft inner shoulders contact the thrust
washers.
46
11. Place the planetary spider on a workbench
with the flange end facing UP.
!
WARNING
When you apply some silicone gasket materials,
small amounts of acid vapor are present. To
prevent possible serious injury, the work area
must be well ventilated. If the silicone gasket
material gets into your eyes, flush them with
water for 15 minutes. Have your eyes checked by
a doctor as soon as possible.
13. Install the O-ring at the base of the wheel hub
flange.
14. Install the planetary ring gear onto the ring
gear hub.
Planetary Spider Assembly
NOTE: For correct installation, the planetary
pinions must contact both the sun gear and the
ring gear before installation.
1. Install the planetary spider and gearing
assembly onto the wheel hub.
2. Install the slotted head machine screws that
temporarily secure the planetary spider to the
wheel hub. Hand tighten the screws. Seat the
head of each screw below the surface of the
spider flange.
Section 5
Assembly
3. Mount the inner and outer wheels. Install the
wheel nuts and tighten them to the vehicle
manufacturer’s specification.
NOTE: The PRC 775 axle has a common oil level
between the carrier and the wheel ends. The wet
disc brakes must also be filled separately. Five
locations must be filled. The vehicle must be on a
level surface when filling. Fill to the bottom of
each fill plughole. Wait and allow the oil to flow
through the axle. Check the oil level again after a
few minutes and fill to the specified level if
necessary.
4. Add the correct axle lubricant into each wheel
end through the fill/level hole in the planetary
spider at the horizontal position (three or nine
o’clock).
5. Add the correct lubricant to the axle housing
bowl area.
6. Apply sealant to the threads of the fill/level plugs.
7. Install the fill/level plugs and tighten them to
35 lb-ft (47 N•m).
Fill Wet Disc Brakes with
Hydraulic Fluid
1. Fill the wet disc brakes with tractor oil universal
(TOU) fluid by using the 0.875"-14 UNF
O-ring plug near the top of the brake and a
0.875"-14 UNF O-ring plug above the three or
nine o’clock position. Fill the brakes until oil
exits the lower plug (above the 3 or 9 o’clock
position).
2. Connect brake coolant lines and brake
actuation lines at the proper locations.
NOTE: Brake coolant inlet is connected to the
0.875"-14 UNF O-ring plug at the top position of
the brake between the mounting bolts. The brake
actuation line is connected at the 0.5625"-18 UNF
plug at either the three or nine o’clock position.
3. Thoroughly bleed all air from brake actuation
system.
47
Section 6
Specifications
PRC 425 Q Plus™ Wheel End Torque Chart
1
8
7
2
6
3
4
5
Item
48
Fastener
Torque Value
1
Wheel rim nut
Per OEM specification
2
Pinion shaft set screw
35 lb-ft (47 N•m)
3
Oil fill/level/drain plug
35 lb-ft (47 N•m)
4
Planetary spider-to-wheel hub slotted head screw
Hand tighten (no specification)
5
Spindle and brake spider mounting (drum)
200-260 lb-ft (270-350 N•m)
6
Camshaft bracket clamp
35-50 lb-ft (47-68 N•m)
7
Camshaft bracket to spider
85-115 lb-ft (115-156 N•m)
8
Wheel bearing adjusting nut
Refer to instructions in Section 3.
Section 6
Specifications
PRC 425 W3H Wheel End Torque Chart
1
6
3
4
5
2
Item
7
Fastener
Torque Value
1
Wheel rim nut
Per OEM specification
2
Spindle and wet disc brake housing mounting
370-480 lb-ft (500-650 N•m)
3
Wheel bearing adjusting nut
Refer to instructions in Section 3.
4
Brake housing capscrews
200-258 lb-ft (270-350 N•m)
5
Pinion shaft setscrew
35 lb-ft (47 N•m)
6
Oil fill/drain plug (not shown)
35 lb-ft (47 N•m)
7
Piston return spring shoulder bolts
22-30 lb-ft (30-40 N•m)
49
Section 6
Specifications
PRC 775P Wheel End Torque Chart
1
7
2
3
8
4
6
5
Item
50
Fastener
Torque Value
1
Wheel rim nut
Per OEM specification
2
Lock plate screw
20-30 lb-ft (27-41 N•m)
3
Wheel bearing adjusting nut
Refer to instructions in Section 5.
4
Planetary spider-to-wheel hub slotted head screw
Hand tighten (no specification)
5
Camshaft bracket to spider
85-115 lb-ft (115-156 N•m)
6
Camshaft bracket clamp
35-50 lb-ft (47-68 N•m)
7
Spindle and brake mounting
370-480 lb-ft (500-650 N•m)
8
Oil fill/drain plug
35 lb-ft (47 N•m)
Section 6
Specifications
PRC 775 W3H Wheel End Torque Chart
1
4
2
3
6
5
7
Item
Fastener
Torque Value
1
Wheel rim nut
Per OEM specification
2
Lock plate screw
20-30 lb-ft (27-41 N•m)
3
Wheel bearing adjusting nut
Refer to instructions in Section 5.
4
Spindle and wet disc brake mounting
370-480 lb-ft (500-650 N•m)
5
Brake housing capscrews
200-258 lb-ft (270-350 N•m)
6
Oil fill/drain plug
35 lb-ft (47 N•m)
7
Piston return spring shoulder bolts
22-30 lb-ft (30-40 N•m)
51
Section 6
Specifications
Lubrication Specification
NOTE: Do not fill only through the axle housing
bowl. For axles with a common level, fill the axle
at each wheel end and the axle housing bowl to
the bottom of the fill/level plug hole with the
specified oil. Wait and allow the oil to flow
through the axle. Check the oil level again and fill
to the specified level if necessary.
Lubrication Schedule
Operation
Off-Highway➀
Initial Oil Change
250 operating hours➀
Check Oil Level
250 operating hours➀
Petroleum Oil
Change
1,500 operating hours or twice a year
(whichever comes first)➀
Synthetic Oil or
Semi-Synthetic Oil
Change
3,000 operating hours or once a year
(whichever comes first)
➀ The interval depends on the individual operating conditions, speeds and loads. Severe operating conditions may
require more frequent intervals.
Lubrication Specifications
Outside Temperature
AxleTech
Specifications
Military
Specification
Approval
°C
Min.
Max.
Min.
Max.
GL-5, SAE 85W/140
10
None
-12
None
GL-5, SAE 80W/90
-15
None
-26
None
O-76E, Gear Oil
GL-5, SAE 75W/90
-40
None
-40
None
O-76L, Gear Oil
GL-5, SAE 75W/140
-40
None
-40
None
O-76M, Gear Oil
GL-5, SAE 75W/140
-40
None
-40
None
O-76N, Gear Oil
GL-5, SAE 75W/140
-40
None
-40
None
O-76A, Gear Oil
O-76D, Gear Oil
MIL-PRF-2105-E
Specification
Oil Description
Tractor oil
universal (TOU)
SAE 10W, 20W or 10W30
NOTE: Refer to AxleTech Maintenance Manual 1,
Lubrication, for further lubrication information.
To order this publication, call AxleTech
International’s Customer Service Center at
877-547-3907 or send a fax to 866-547-3987.
52
°F
Oil
Description
Section 6
Specifications
Wet Disc Brake Coolant Specifications
Sump and Forced Cooling Systems with Hub Seals
Coolant
Specification
Petroleum Base
SAE 10W, SAE 20W or SAE 10W30
See the recommendations of the vehicle manufacturer.
• Use tractor oil universal fluid (“TOU” types)
formulated for wet disc brakes in the wet
disc brake housing. Make sure that the
specifications of the tractor fluid are the
same as the specifications of the vehicle
manufacturer.
!
CAUTION
The operating temperature of the coolant must
never reach or exceed 250°F (120°C). If the
operating temperature of the coolant reaches or
exceeds 250°F (120°C), the internal components
of the brake will be damaged. A forced cooling
system may be required to assure the coolant
temperature remains below 250°F (120°C).
Coolant Change Intervals
Break-In Interval:
Change the fluid in the brake housing after the first month or the first 200-250 hours of
operation, whichever comes first.
Normal Maintenance Interval:
Change the fluid every 6 months or every 3000 hours of operation, whichever comes first.
Hydraulic Fluid Specifications
Use only the brake hydraulic fluid specified by the manufacturer of the vehicle. Do not use different hydraulic fluids. The wrong
fluid will damage the seals on the piston.
53
Notes
Notes
Notes
Suite 400
3001 West Big Beaver Road
Troy, Michigan 48084
U.S.A.
Toll Free: 877-877-9717
Non-Toll Free: 248-816-5401
FAX: 248-435-1990
Website: www.axletech.com
AxleTech, International France
4, Rue Jean Servanton
Boite Postale 656
42042 Saint Etienne Cedex 1
France
(33) 477.92.88.00
FAX: (33) 477.92.88.93
MM-9K
Revised 02-01
© Copyright AxleTech International
Printed in the USA
AxleTech do Brasil Sistemas Automotivos Ltda.
Avendia Joao Batista, 830
Centro-Osasco-SP
06097095 Brasil
Phone: +55 11 36846641
FAX: +55 11 36846859