B HT-212-M M
CHAPTER 65 - TAIL ROTOR DRIVE SYSTEM
CONTENTS - MAINTENANCE PROCEDURES
Chapter/Section
Number
Number
65-00-00
65-00-00
5
5
65-00-00
7
65-00-00
65-00-00
65-00-00
65-00-00
7
12
18
Tail rotor drive system ...........................
Troubleshooting ...............................
00
(°7
65-1
65-1
65-2
65- 2
Title
0101
Paragraph
Number
Page
PO,
((DD
...............
(CD
Tail rotor driveshafts ..........................
Driveshaft hangers ............................
Alignment - tail rotor drive system ............
Deleted
.......................................
00000
00000
Tail rotor driveshafts and hangers
00000
66666
LC)
65-4
65- 4
65-10
65- 10
65-16
65- 16
65-17
65- 17
.ca)
LC)
(0(0(0(0(0)
65-3
65- 3
900
00000
00000
00000
00000
TAIL ROTOR DRIVESHAFTS AND HANGERS
24B
LC)
0
35
35
36
40
40
LC)
LC)
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
LC)
LC)
25
25
30
LC)
LC)
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
65-00-00
LC)
L()
Intermediate (42°) gearbox ......................
Maintenance ..................................
Sight glass ....................................
Chip detector .................................
Oil filler cap ...................................
Flexible couplings .............................
000000
000000
LC)
65-18
65- 18
65-19
65- 19
65-29
65- 29
65-33
65- 33
65-37
65- 37
65-42
65- 42
000000
000000
000000
000000
INTERMEDIATE GEARBOX
31
32
32
00000000
00000000
00000000
00000000
717
¢O)
LC)
LC) LC) LC) LC)
070000000
LC)
LC)
Removal
Installation
Sight glass
LC)
LC)
65-61
65-61
65-66
65- 66
65-67
65- 67
.........................
.......................................
....................................
....................................
Chip detector .................................
Oil filler cap ...................................
Tail rotor gearbox flexible coupling ..............
Lubrication ....................................
Tail rotor (90°) gearbox
00000000
00000000
00000000
00000000
00000000
65-44
65- 44
65-45
65- 45
65-50
65- 50
65-52
65- 52
65-56
65- 56
0)0)0)0)0)0)0)0)
TAIL ROTOR GEARBOX
41
43
43
FIGURES
Figure
Number
Number
Qom
Tail rotor driveshaft and hangers ......................................
Damage limits - tail rotor driveshaft ...................................
Tail rotor driveshaft hanger assemblies ...............................
Deleted
................................................................
8
10
14
(fl
65-1
65-1
65-2
65- 2
65-3
65-4
65- 4
65-4A
65- 4A
Page
Title
16A/1 613
Tail rotor driveshaft coupling "TEMP-PLATES" condition and
correction .............................................................
Rev.5
17
65-00-00
Page 1
B H T-212-M M
FIGURES (Cont)
Figure
Number
C).
-.-.
con
Tail rotor driveshaft alignment .........................................
Intermediate gearbox ..................................................
Intermediate gearbox sight glass ......................................
Chip detector ..........................................................
Chip detector damage limits ...........................................
Oil filler cap ...........................................................
Tail rotor gearbox
.....................................................
Tail rotor gearbox pusher T101264-103 tool application
..............
21
28
31
33
33
C'7
34
37
38
1^^
1^^
Sight glass ............................................................
41
Tail rotor gearbox electrical chip detector
42
1^^
I^^
.............................
Tail rotor gearbox electrical chip detector damage limits ..............
Tail rotor gearbox oil filler cap ........................................
-0-0
1^^
65-10
65- 10
65-11
65-12
65- 12
65-13
65- 13
65-14
65- 14
65-15
65- 15
65-16
65- 16
Number
z
(DD
I^^
65-5
65- 5
65-6
65- 6
65-7
65- 7
65-8
65- 8
65-9
65- 9
Page
Title
43
44
TABLES
Table
Number
Title
Troubleshooting - tail rotor drive system ..............................
Troubleshooting - intermediate gearbox ...............................
65-00-00
Page 2
Rev. 5
11^^
65-1
65-1
65-2
65- 2
Page
Number
5
25
BHT-212-MM
TAIL ROTOR DRIVE SYSTEM
65-1.
TAIL ROTOR DRIVE SYSTEM.
This chapter contains maintenance
65-2. TROUBLESHOOTING.
table65-1
65-1 for troubleshooting tail
Refer to table
rotor drive system problems.
information on tail rotor driveshafts, couplings
and hanger assemblies, intermediate (420)
gearbox, and tail rotor (90°) gearbox.
Table 65-1. Troubleshooting - tail rotor drive system
INDICATION OF
TROUBLE
PROBABLE CAUSE
CORRECTIVE ACTION
originating in tail rotor drive loose.
(D-0
Vibration believed to be Bolts in V-band couplings Inspect all V-band clamps for
a0'
loose bolts. Tighten or replace
as required.
system.
support.
(a)
Broken hanger or hanger Inspect hangers and supports
(CD
for cracks. Replace defective
parts.
0
Tail rotor driveshaft out of Verify driveshaft balance
balance.
weights are secure. The
balance weights are small metal
strips bonded to driveshaft (one
empty bonded space should be
open where a bonded test strip
was removed during
(u'-
manufacture). If more than one
space is open, a balance weight
is missing. Replace driveshaft.
brown).
-ti
(/)
SS)
discoloration (from green to
U-0
Visual overheat indicator Shaft hanger bearings rough Check for signs of overheated
stripe(s) on hanger shows or overheating.
bearings. If no sign of
overheating is noted, recheck
after five hours of operation.
^''
Replace bearings if overheating
is evident. Replace bearings, if
rough, after five hours of
operation, whether or not
((DD
overheating.
Excessive loss of grease from Misalignment of bearing in
hanger bearings.
hanger.
Check and correct alignment of
bearings.
65-00-00
Page 5
BHT-212-MM
Table 65-1.
Troubleshooting - tail rotor drive system (Cont)
INDICATION OF
TROUBLE
PROBABLE CAUSE
CORRECTIVE ACTION
0)0
Binding or roughness when Dry or faulty hanger bearings. Lubricate bearings.
rotor and tail rotor driveshaft
is turned by hand.
Inspect electric chip detectors in
...
.1.
intermediate and tail rotor
gearboxes for evidence of
internal failure. Replace
c.>
defective gearbox.
65-00-00
Page 6
(')
0
0
(D
Faulty tail rotor gearbox.
B HT-212-M M
TAIL ROTOR DRIVESHAFTS AND HANGERS
65-3. TAIL ROTOR DRIVESHAFTS AND
HANGERS.
3. Push shaft (1 or 3) against spring-loaded
flexible coupling to disengage opposite end.
Remove shaft.
Five of the six tail rotor driveshafts are of the
C)5)
same length. Number two shaft, located
0_.5.
below engine tailpipe area, is shorter. Each
Cleaning.
65-6.
6,°
shaft is an anodized aluminum alloy tube with
face-splined couplings riveted on both ends,
<30
0(b
3--
and is dynamically balanced by metal strips
bonded on each end of tube. Hinged covers
with cowl-fasteners provide access to shafts
along tailboom and on the vertical fin.
Tail rotor driveshaft hanger assemblies are
mounted on three supports on the tailboom
and one support on the engine deck (figure
figure
MATERIALS REQUIRED
Refer to BHT-ALL-SPM
BHT-ALL-SPM for specification and
source.
NUMBER
NOMENCLATURE
C-304
C-304
Solvent
.ZS
O'.
65-1
65-1).
Each consists of a flexible and a
nonflexible coupling attached on a splined
shaft mounted through a sealed single-row
bearing in a ring-shaped hanger. The hanger
has two mounting lugs and is attached to
CAUTION
.fl
DO NOT ALLOW SOLVENT TO
(r-
hanger fittings with bolts. Hanger fittings are
prealigned with permanent shims on tailboom
structure.
m
SATURATE DRIVESHAFT.
.-:
1.
Clean driveshaft with clean, lint-free cloth
dampened in solvent (C-304).
C-304
TAIL ROTOR DRIVESHAFTS.
Dry with filter, compressed air.
2.
1.
Removal.
65-7.
Open hinged covers along top of
3'o
(J1
65-5.
tailboom and on front of vertical fin. Open
engine cowling.
1.
Inspection.
((DD
65-4.
Inspect driveshafts in accordance with
figure
65-2.
figure 65-2
Check two water drain holes are not
clogged on contoured surface of curvic
2.
4.
DO NOT INTERMIX PARTS OF
5.
Remove clamp sets (8, figure
65-1) at
figure 65-1
both ends of each shaft (1 or 3). Reassemble
clamp set to prevent intermixing of parts.
-I<
Inspect shaft for distortion (figure
65-2).
figure 65-2
Inspect balance weights for security. Any
weights found debonded may be rebonded. If
weight is missing, replace driveshaft.
Inspect clamp sets for cracks, worn bolt
holes, and distortion. Damage which can be
6.
65-00-00
Rev.5
icon
2.
fully meshed without clamps.
OF SHAFT.
CLAMP SETS.
w(a
COUPLING UNLESS CLAMP SET
IS REMOVED FROM BOTH ENDS
Inspect curvic coupling splines on face of
shaft coupling. There shall be no radial play
or backlash between mating couplings when
(.)
OF SHAFT FROM MATING
3.
(ten
DO NOT DISPLACE EITHER END
coupling.
CL-0
CAUTION
Page 7
BHT-212-M M
CLAMP SET
TORQUE
30 TO 35 IN-LB
(3.39 TO 3.96 Nm)
ABOVENUT
Clamp set
Hanger fitting
Nut
Nut
Nut
Nut
15.
16.
17.
18.
19.
Bearing
Outer coupling
Hanger bolt hole
Non-flex coupling
Seal
20.
"TEMP-PLATES"
m`°
8.
9.
10.
11.
12.
13.
14.
.r-
2.
3.
4.
5.
6.
7.
Shaft
Hanger support fitting (engine deck)
Short shaft
Hanger bearing assembly
Hanger support fitting
Intermediate gearbox
Tail rotor gearbox
(03
1.
Visual OVERTEMPERATURE
indicator stripe
NOTES
A
Chapter 65
65)
Location of temperature indicator TEMP-PLATES on outer couplings. (BHT 212-CR&O, Chapter
v_,
A Torquing sequence is as follows:
A
10, 12, 13, and 11.
Clamp halves shall be kept together as a set.
(DD
Location of hanger bearing assembly visual overtemperature indicator stripe. (BHT 212-CR&O,
Chapter 65
65)
Chapter
212-M-65-1
Figure 65-1. Tail rotor driveshaft and hangers
65-00-00
Page 8
Rev.5
B HT-212-M M
1.
clamp set.
damage from driveshaft within limits (figure
figure
65-2 using 400 to 600 grit abrasive cloth or
65-2)
Damage which can be
detected visually requires replacement of
clamp set.
(3D
32 RMS or better.
Inspect clamp sets for mechanical
0
((DD
Damage exceeding this limit is not acceptable
and shall be repaired or entire clamp set
replaced. Inspect remaining surfaces of
-coca
not exceeding 0.010 in. (0.254 mm) is
Touch up paint to match surrounding
area.
5.
(t/
E
Damage
exceeding this limit is not acceptable and
Apply one coat of primer (C-202).
C-202
4.
E
(fit
clamp set for mechanical damage. Damage
3. Treat repaired areas with chemical film
material (C-100)
C-100 (BHT-ALL-SPM).
BHT-ALL-SPM
E
(0.203 mm) is acceptable without repair.
acceptable without repair.
exceeded.
`o-
000wE cop
LOR3
damage on spot face, lug fillets, and internal
groove. Damage not exceeding 0.008 in.
When surface rework is
complete, verify damage limits are not
shall be repaired or clamp set replaced.
Rebond loose balance strip as follows:
6.
0
8.
2. Radius in reworked area shall be 0.50 in.
(12.7 mm) or greater. Surface finish shall be
0
a-C
internal groove.
paper (C-423).
C-423
m3-
3-(n
5'w
Inspect clamp sets for gouges or wear
pattern extending into fillet radius at bottom of
(sue
+-i
7.
Polish out mechanical and corrosion
nom
0
detected visually requires replacement of
a. Clean balance weight and shaft in area
where weight will be bonded by abrading
lightly with 400 grit abrasive cloth or paper
Repair.
65-8.
(C-423).
C-423
MATERIALS REQUIRED
Chemical Film Material
C-202
C-202
P ri mer
C-305
C-305
Aliphatic Naphtha
C-317
C-317
Adhesive
C-423
C-423
Abrasive Cloth or
Remove sanding residue with a clean,
lint-free cloth dampened with aliphatic
naphtha (C-305).
C-305
c. Mix adhesive (C-317)
C-317 33 parts B to 100
parts A. Mix parts thoroughly. (Pot life is 30
to 50 minutes after mixing.)
0
C-100
C-100
Paper
d. Apply a thin coat of adhesive to
balance weight and shaft in area where
-.w
(On
NOMENCLATURE
jai
NUMBER
'D'0
b.
weight will be bonded.
X3.0
e. Place a 6 to 10 mil thread in adhesive
(OD
on balance weight to act as a spacer and
control bondline thickness.
mm
m.pmm
DRIVESHAFT SHALL BE CHECKED
AND REBALANCED AS REQUIRED
IF REWORKED AREA IS 8.0 SQ.
IN. (51.6 SQ. CM) MORE ON ONE
using rubber bands or equivalent.
g. Allow adhesive to cure at 70 to 95°F
(21 to 350C) for 24 hours. Accelerated cure
may be accomplished by heating area to 175
to 190°F (79 to 88°C) for 60 minutes.
h. Apply chemical film material (C-100)
C-100 to
E
SIDE THAN THE OTHER.
(Q'
m
m
TO REMOVE DAMAGE.
+-:
DO NOT USE GRINDING WHEEL
f. Position weight on shaft. Maintain
approximately 10 psi pressure on weight
0-0
CAUTION
"-'
balance weight and appply touch up paint, if
required.
65-00-00
Page 9
BHT-212-MM
O
AREA B
0
DAMAGE LOCATION SYMBOLS
AREA A
TYPE OF DAMAGE
AREA B
MAX IMUM DEPTHS AND REPAIR AREAS ALLOWED
AFTER POLISHING OUT
CRACKS ALLOWED
See Note 6
See Note 6
NICKS AND SCRATCHES
0.008 Inch
(0.203 mm)
0.012 Inch
(0.304 mm)
SHARP DENTS
0.010 Inch
(0.254 mm)
0.015 Inch
(0.381 mm)
NONSHARP DENTS
0.020 Inch
(0.508 mm)
0.030 Inch
(0.762 mm)
NOTES
ays
c-.-3
Damage defined on the chart above is acceptable if repaired as follows:
a. Damage is polished out with fine abrasive cloth with minimum radius of 0.5 inch (12.70
millimeters) and with surface finish of 32 RMS or better.
b. Maximum depth after rework does not exceed limits shown in chart.
c. Reworked area is treated for corrosion prevention.
d.
3.
If rework area is eight square inches more on one side than the other, shaft balance must
be checked.
Loss of one or more balance weights is cause to replace driveshaft. One empty bonding
space should be open where bond test coupon was removed. If more than one empty space
is observed, replace driveshaft.
Damaged curvic coupling splines that result in radial play and/or backlash between
stn
2.
0
a=te
1.
assembled couplings when fully meshed without clamps are not acceptable.
212-M-65-2-1
Figure 65-2.
65-00-00
Page 10
Damage limits - tail rotor driveshaft (sheet i of 2)
B HT-212-M M
5.
If tail rotor driveshaft distortion is suspected, support driveshaft on "V" blocks and measure
(J1
Grooves worn on shaft coupling by clamp to extent that wear prevents proper clamping are
cause to replace driveshaft.
(')
4.
(J1
3°d
t/1
-03<'
'-`""s
-ti
03:30
3'3 aid
Any crack in a driveshaft is cause to replace the affected driveshaft except cracks in rivet
heads are acceptable if they do not exceed the following limits:
a.
Cracks are approximately radial when viewing top of shop head.
b. No crack extends into an area with a diameter less than 1.25 diameters of rivet shank.
c. Cracks do not intersect.
d. The minimum distance between cracks is less than one shank diameter.
e. A maximum of 3 such cracks.
f. Crack width does not exceed 0.06 inches (1.52 millimeters) times rivet shank diameter.
g. Maximum or ten percent of rivet shop heads may have cracks within above limits.
d3m
6.
0
2E°_
run out. Maximum acceptable total indicator reading on long shafts is 0.050 inch (1.27
millimeters). Maximum acceptable total indicator reading on short shaft is 0.020 inch
(0.508 millimeters). Do not attempt to straighten driveshaft.
(fl
212-M-65-2-2
Figure 65-2.
65-9.
Damage limit - tail rotor driveshaft (sheet 2)
Installation.
NOTE
All nuts used on a clamp must be of
the same type and style.
Tail rotor driveshaft clamps (8, figure
figure
Adjust clamp set halves to obtain
equal gaps at both ends within 0.030
in. (0.732 mm).
are matched sets. Keep in
one clamp half, or if clamp halves
rematched with one of equal weight
within one gram.
3. Tighten clamp bolts evenly, torque 30 to
35 in.lbs. (3.39 to 3.95 Nm) above nut friction.
C-0
are intermixed, each shall be
E
sets after removal to maintain
balance. If it is necessary to replace
Q'<
65-1
65-1)
^O''
U))
NOTE
Driveshaft clamp nuts are self-locking and
shall not be reused unless tare torque is a
minimum of 3.5 in.lbs. (0.395 Nm). Torque
sequence is as follows: 10, 12, 13, and 11
(figure
65-1). Tap lightly around outer surface
figure 65-1
to seat clamp, and recheck torque.
gearboxes.
4.
2.
Install matched clamp sets (8) on
couplings, with bolt heads to direction of
_-C
Position each shaft (1 or 3, figure
65-1)
figure 65-1
between mating couplings of hangers (4) and
cep
1.
Close covers and cowling.
rotation and clamp joints indexed 90° to those
of adjacent clamps for balance in operation.
65-00-00
Page 11
BHT-212-M M
65-10.
DRIVESHAFT HANGERS.
CAUTION
65-11.
Removal.
DO NOT IMMERSE HANGER
CAUTION
ASSEMBLY IN SOLVENT.
i
Clean external surfaces of hanger assembly
with a clean, lint-free cloth dampened with
,OD
DO NOT DISPLACE EITHER END
OF DRIVESHAFT FROM MATING
COUPLING UNLESS CLAMP SET
IS REMOVED FROM BOTH ENDS
OF SHAFT. FAILURE TO COMPLY
MAY RESULT IN DAMAGE TO
C-304
solvent (C-304).
Do not allow solvent to
contact internal surfaces of hanger
assemblies.
65-13.
HANGER BEARING AND/OR
MATERIALS REQUIRED
CURVIC COUPLING.
Remove tail rotor driveshafts from each
end of hanger to be removed (paragraph
65paragraph 651.
5).
5
Remove two bolts (19, figure
65-3),
figure 65-3
(DD
(`.
washers (20, 22, 23, and 25), and nuts (26).
Remove hanger assembly from support (17).
Remove two bolts (27) and washers (28).
Remove hanger assembly (5) from fitting (16).
4.
NUMBER
NOMENCLATURE
C-454
C-454
India Stone
Inspect hanger bearing (4, figure
65-1)
figure 65-1
1.
for cracks, elongated bolt holes, or other
visible damage.
(F)
3.
Refer to BHT-ALL-SPM
BHT-ALL-SPM for specification and
source.
Inspect outer coupling (16) temperature
indicator "TEMP-PLATES" (20) as follows:
2.
Remove hanger assembly (9) same as
previous step.
Overtemperature indicator dots on
"TEMP-PLATES" are white or light
off- c'-
65-12.
NOTE
Cleaning.
gray color and turn black when
exposed to an overtemperature
MATERIALS REQUIRED
condition. Chemical contamination
Refer to BHT-ALL-SPM
BHT-ALL-SPM for specification and
can also cause indicator DOTS to
source.
turn black.
C-304
C-304
Solvent
Temperature indicator "TEMPPLATES" must not show evidence of
a.
o>00
NOMENCLATURE
a"'
NUMBER
overtemperature, deterioration, debonding, or
0."
2.
Inspection.
NOTE
>'_
>F-
discoloration of the epoxy coating that
prevents interpretation of the indicating
DOTS. If any of these conditions exist,
proceed to step b.
:7CD
icy
Rev.5
E
65-00-00
Page 12
same coupling) is discolored or shows
mechanical damage or degradation of the
-0)
CR&O for instructions to clean
CR&O
disassembled hanger(s).
b.
If one "TEMP-PLATE" is missing, and
no DOT on the other "TEMP-PLATE" (on the
w'Q
These instructions are applicable to
assembled tail rotor driveshaft
BHT-212hanger(s) only. Refer to BHT-212-
BHT-212-MM
Inspect seal (14) for protrusions,
leakage, cuts, tears, and deterioration.
5.
p
0)--
U
O
3O3
O
movement of grease shields,
ova)
0
O
.,.
'V)
O
O\`.
O
O
O
_
U
p
Inspect bearing (15) in hanger support
fitting (5) and outer coupling (16) for grease
leakage. Grease leakage of adjacent areas by
6.
OO
O
Q
U
U
o
OU
QQN
Q(0
o
0
O
0
O
Q
.c
moved.
green to brown) indicates a possible overheat
0-0
O
00
Q
U
o
Q
U
change in color of indicator stripe(s) (from
(BHT-212-CR&0)
BHT-212-CR&O
QO
O
U
>
service whose witness marks
indicate that the grease shield has
discoloration and overheat condition. A
condition and/or component degradation.
Cause of discoloration shall be determined
and corrected prior to continued operation
O
NO
figure 65-1
overheat indicator stripes (19, figure
65-1) for
0
indicated by breakage of witness
marks. Remove any bearing from
Inspect hanger bearing assembly visual
,.,,
O
U
o
O
Inspect hanger bearing for
action.
0
w0-icw
0
N
NOTE
probable cause and required corrective
2a.
o
CR&O).
CR&O
O
U
OO
O
b. should be replaced as soon as practical. If
any indicator DOT on "TEMP-PLATE" has
changed color to black, see figure 65-4A for
-
Replace unserviceable seals (BHT-212BHT-212U
U
J
U
W
The discrepant "TEMP-PLATE" in step
C.
o
>
returned to service.
°
o
U
>
epoxy overcoating, the helicopter may be
U
UX
grease is cause for replacement with the
following exception: A small amount of grease
Inspect outer coupling (16) for nicks,
dents, and cracks. Minor damage which can
leakage as follows:
O
O
o
coo
OO
o
Q
OU
O
_
OO
-
4.
expelled from around tip of bearing seals
indicates a slight overlubrication and is not
cause for hanger replacement. If leakage is
detected, perform an evaluation of grease
-I,
O
O
Inspect nonflexible couplings for nicks,
dents, and cracks. Minor damage which can
be polished out with fine India stone (C-464)
C-464
is acceptable.
3.
OO
o
U
UQ
o
-
O
be polished out with fine India stone (C-464)
C-464
is acceptable.
U
O
ON
65-00-00
Page 12A/12B
N
Rev.5
B HT-212-M M
Hanger bearing assembly (15)
b.
CAUTION'
is
excessively worn or cracked.
Curvic face of couplings are
C.
DO NOT CLEAN OR SPRAY
excessively worn.
BEARING HANGER ASSEMBLY
WITH ANY TYPE OF SOLVENT
Couplings show signs of overheating,
or being run without lubricant.
a=.
-6-0
--U
d.
Z
DURING INSPECTION. USE CLEAN
CLOTH TO CLEAN EXTERIOR OF
Hanger support fitting shows signs of
°)O)
e.
HANGER ASSEMBLIES.
overheating.
a.
Wipe grease from outer coupling (16),
and bearing (15) in hanger support fitting (5).
Record which bearing is leaking and
O)°
b.
monitor bearing condition for the next ten
flight hours.
f.
Hanger support fitting shows signs of
metal particles and/or rust colored fretting
debris near bearing.
10.
Lubricate hanger bearing assemblies as
required (paragraph
65-14).
paragraph 65-14
0.c
caw
If the amount of grease expelled from
C.
bearing seal does not decrease after this
65-14.
Inspect bearing (15) in hanger support
fitting for wear, roughness and binding as
1.
Remove tail rotor driveshaft sections
attached to hanger bearings assemblies to be
lubricated (paragraph
65-5).
paragraph 65-5
period of time, replace hanger assembly.
0
7.
follows:
Remove driveshaft from each side of
hanger bearing assembly.
a.
'.0
°)c
o0)
b.
Rotate bearing while pressing in
axially on nonflexible coupling and at hanger
0--5
COQ
L-0
bearing assembly. Bearing may feel smooth
when turned with no load, but rough when
loaded by pressing in with hand. Obvious
roughness, catching, or binding when turned,
by hand, is cause for replacement of hanger
bearing assembly.
Remove tail rotor driveshaft hanger
assemblies (paragraph
paragraph 65-11).
65-11
3.
Clean tail rotor driveshaft
assemblies (paragraph
paragraph 65-12).
65-12
hanger
Disassemble, lubricate, and re-assemble
tail rotor driveshaft hanger assemblies (BHTBHT4.
212-CR&O).
212-CR&O
5.
Install tail rotor driveshaft hanger
assemblies (paragraph
paragraph 65-15).
65-15
Inspect engine deck hanger, support
1-.
8.
2.
Lubrication.
fittings and hanger support fitting for
NOTE
Mechanical damage in excess of superficial
and corrosion damage which can be detected
visually is not acceptable.
Ground run and leak check must be
(On
-_T
mechanical and corrosion damage.
performed following installation of
new, repaired, or relubricated
flexible couplings.
aim
9.
Replace driveshaft hanger assemblies for
the following conditions:
Make an entry in helicopter log and in
c_0
a.
Bearing is rough, binds when rotated,
or shows excessive wear.
6.
flex couplings lubrication log of date
lubricated, date grease manufactured and
helicopter hours (Chapter
12).
Chapter 12
L()
Rev.5
65-00-00
Page 13
BHT-212-MM
1.
Drive quill (transmission)
07,
S.<
2. Tail rotor driveshaft
3. Hanger assembly
4. Tail rotor driveshaft
5. Hanger assembly
6. Tail rotor driveshaft
7. Hanger assembly
8. Tail rotor driveshaft
9. Hanger assembly
10. Tail rotor driveshaft
11. Intermediate gearbox assembly
12. Tail rotor driveshaft
13.
14.
15.
16.
17.
18.
19.
20.
21.
Tailboom
Fitting
Fitting
Fitting
Support
Flexible coupling
Bolt
Steel washer
Grease fitting
22. Aluminum washer
23.
24.
25. Steel washer
26. Nut
27. Bolt
28. Thin steel washer
29. Barrel nut
30. Bolt
31. Thin steel washer
32. Aluminum washer
33. Thin steel washer
34. Nut
Steel washer
Brace assembly
212-M-65-3-1
Figure 65-3. Tail rotor driveshaft hanger assemblies (sheet 1 of 2)
65-00-00
Page 14
B HT-212-M M
DETAIL A
DETAIL B
DETAIL C
212-M-65-3-2
Figure 65-3. Tail rotor driveshaft hanger assemblies (sheet 2)
FOR BEST VALUE, BUY GENUINE BELL PARTS
Rev.3
65-00-00
Page 15
BHT-212-MM
Installation.
3.
(J)
65-15.
Position hanger assembly (7) on fitting
..A
(15) with flexible coupling (18) forward. Install
1.
Position hanger assembly (3, figure
65-3)
figure 65-3
on support (17) with flexible coupling (18)
forward. Install washers (22 and 23) between
support (17) and brace assembly (24) on
each side. Install bolts (19) with washers (20)
assembly (7) and fittings (15). Install washer
(32) next to fitting (15), washer (33), and nut
(34).
Install hanger assembly (9) on fitting (14)
using procedures in previous step.
4.
..+
through hanger assembly (3), support (17),
bolts (30) and washers (31) through hanger
and brace assembly (24). Install washers (25)
and nuts (26).
2.
5.
Position hanger assembly (5) on fitting
(16) with flexible coupling (18) forward.
Ensure barrel nuts (29) are aligned on each
side. Install two bolts (27) and washers (28).
NOTE
Use additional washers (33) if
necessary to obtain proper bolt
((DD
thread engagement.
65-00-00
Page 16
Rev.5
Install tail rotor driveshafts.
B HT-212-M M
212-M-65-4
1
Figure 65-4. Deleted
65-00-00
Rev. 5
Page 16A/16B
BHT-212-M M
PROBLEM
CAUSE
SEE
NOTE
Black
Good
Defect/Instl
1
Black
Black
Overtemp
2
Part Black
Good
Chem Contamination
1
Missing
Good
Defect/Instl
1
Missing
Missing
Possible Overtemp
2
Fn,
((D
!TI
OTHER RED
TEMP-PLATE
E
ONE RED
TEMP-PLATE
NOTES
1.
Resume operation. Defective TEMP-PLATE or improper installation, replace defective TEMP-PLATE as soon
as practical (BHT 212-CR&O).
2.
Coupling overtemp condition is very likely. Remove driveshaft or coupling assembly and perform overtemp
inspection in accordance with BHT-212-CR&O
BHT-212-CR&O and the following instructions. Scrap affected male and
female couplings if any of the conditions listed below exist or if required by BHT-212-CR&O
BHT-212-CR&O inspection
criteria.
a.
Cadmium plating on outer coupling is discolored (circumferential tan or light brown band) or
blistered.
Gear teeth of either coupling are discolored (brown or blue) in normally bright contact patterns.
c.
Under 5x or 10x magnification, surfaces of gear teeth of either inner or outer coupling exhibit signs of
metal smearing or tearing in contact patterns.
d.
Grease is very viscous (thick) and has a strong pungent order.
sari
b.
NOTE
If NONE of the above conditions exist, coupling may be reassembled in accordance
with BHT 212-CR&O and return to service following replacement of TEMP-PLATES.
212-M-65-4A
Figure 65-4A.
Tail rotor driveshaft coupling TEMP-PLATE condition and correction
BUY BELL PARTS - BUY BELL VALUE
Rev.3
65-00-00
Page 17
BHT-212-MM
6.
Operate helicopter (BHT-212-FM)
BHT-212-FM for 5
SPECIAL TOOLS REQUIRED (CONT)
minutes at 100% Nr.
Shut down engine and inspect
NOMENCLATURE
coupling(s) and surrounding structure for
412-240-033-101
Hanger simulator (2)
evidence of grease leakage, remove hanger
assembly and replace defective parts.
412-240-034-101
Hanger simulator
412-240-035-101
Hanger simulator
sac
NUMBER
7.
evidence of grease leakage. If there is
Inspect hangers overheat indicator
0.0
8.
0
stripes for discoloration and overheat
`.0
0
A tail rotor drive system alignment check
1.
coo
condition. A change in color of indicator stripe
(from green to brown) indicates a possible
shall be made whenever driveshaft
degradation. Cause of indicator stripe
airframe structure in area of driveshaft
overheat condition and/or component
misalignment is suspected, when damage to
0-0
212-CR&O
212-CR&O).
Inspect flexible couplings
are performed in any area of tailboom or in aft
section of forward fuselage, or when original
intermediate gearbox is replaced with
-i3
to paragraph
65-13.
paragraph 65-13
_°)
+-a)
temperature indicator "TEMP-PLATES". Refer
-^`
corrected prior to continued operation (BHTBHT-
7z-
c.0
0
hangers requires structural repair or parts
replacement, when major structural repairs
ate-.
discoloration shall be determined and
a
gearbox of a different part number. Alignment
SYSTEM.
of driveshaft hanger supports and
0_0
LL)
65-16. ALIGNMENT -TAIL ROTOR DRIVE
intermediate gearbox shall be accomplished
0
0
as follows:
MATERIALS REQUIRED
Open tail rotor driveshaft covers and
a.
Refer to BHT-ALL-SPM
BHT-ALL-SPM for specification and
source.
intermediate gearbox cover.
b.
Remove tail rotor driveshafts and
hangers (paragraphs
65-4 and 65-10).
paragraphs 65-4
65-10
NUMBER
NOMENCLATURE
C-001
C-001
Grease
C-305
C-305
Aliphatic Naphtha
C-309
C-309
Methyl- Ethyl -Ketone
NOTE
Do not remove driveshaft hanger
support assemblies from tailboom or
forward fuselage.
Adhesive
C-508
C-508
Lockwire
Remove intermediate gearbox
C.
paragraph 65-28
(paragraph
65-28). Ensure any shims
-.a
C-317
C-317
=033
(MEK)
b e t ween
gear b ox and tailboom remain in their
original locations on tailboom.
SPECIAL TOOLS REQUIRED
Alignment plate
T103225-109
Bushing
65-00-00
Page 18
Rev.5
E
T1 03335-1 1 9
f. Clean surfaces on tailboom and hanger
supports where hangers and gearboxes were
removed of primer and sealant. Use a plastic
0
.'.'
simulator
C-,
Intermediate gearbox
T103224-101
e. Remove tailboom from helicopter and
place in suitable support cradle (Chapter
53).
Chapter 53
0
0
simulator
07<
Tail rotor gearbox
T103226-101
((DD
NOMENCLATURE
m-3-0
NUMBER
_-l
0
d.
Remove tail rotor gearbox (paragraph
paragraph
65-54).
65-54
scraper and a clean cloth moistened with
MEK (C-309)
C-309 or alphatic naphtha (C-305).
C-305
BHT-212-M M
Install alignment plate, T103225-119
g.
with T103225-117 bushing for left hand
position of plate (looking aft) (figure
65-5,
figure 65-5
safety wire spinner pliers or other positive
locking pliers.
view A, detail A), on forward tailboom
NOTE
bulkhead using AN8-31A bolt or equivalent
with AN960-816 washer under bolt head.
Ensure wire is still unkinked and is
still positioned in "V" groove in the
(Dm
Install tail rotor/90° gearbox simulator
T103226-101 on top of vertical fin.
A)_
h.
pin in intermediate gearbox
simulator T103224-101.
-'h
M.
Check for alignment of intermediate
gearbox by confirming wire clears the edges
i CAUTION
of holes in top and forward end plates by at
0(a
_0)
SCREWS IN INTERMEDIATE
GEARBOX SIMULATOR ARE
the wire continues to vibrate. If vibration
continues, wire clearance is sufficient to
coo
BACKED OFF SO THEY DO NOT
PROJECT BELOW THE MOUNTING
proceed.
--D
SURFACE OF THE SIMULATOR
BEFORE PROCEEDING.
(SS
If alignment is acceptable loosen 0.020
:30
a-'
grips do not bottom out in mating tailboom
nutplates.
intermediate gearbox simulator T103224-101.
Install the P/N 212-040-003 intermediate
gearbox and then verify that a minimum of
0.030 inch (0.762 mm) clearance exists
between lower surfaces of gearbox (other
than four mounting pads) and underlying
BCD
meos
0-0
sufficient number of AN960-416 and AN960416L washers under heads of bolts so bolt
diameter alignment wire and remove
(i1
L
Install intermediate gearbox simulator
T103224-101 using AN4-13A bolts and
-0-C)
a-3
least 0.005 inch (0.127 mm). See view B. If
alignment is not acceptable, proceed directly
to step m(1). Pluck wire and check to see if
MAKE SURE THREE LEVELING
surfaces of tailboom. If sufficient clearance
exists, proceed directly to step n. If sufficient
? CAUTION
clearance does not exist, add shims (equal
Q(0
amounts at all four mounting pads) as
required to achieve clearance required, then
proceed directly to step m (2).
-°D
BEFORE PROCEEDING.
gearbox simulator T103224-101.
'-F
''.
scraper and a cloth moistened with MEK (CC-
Pass other end of wire through hole in
30(0
(11)
k.
of shim-stacks removed. Using a plastic
.--.
side of plate.
(2) Remove all shims on tailboom at
intermediate gearbox location, note thickness
0
4--
508)
508 in hole of tail rotor gearbox simulator,
T103226-101. Secure end of wire on upper
(TS
Install unkinked 0.020 inch lockwire (CCC.)-0
j.
.-,.
0
(1) Loosen 0.020 inch diameter
alignment wire and remove intermediate
T103225-119 ARE SECURED
(11
OHO
VERIFY TAIL ROTOR GEARBOX
SIMULATOR, T103226-101 AND
BULKHEAD ALIGNMENT PLATE,
309)
309
remove any adhesive or sealant residue
so they project below mounting surface an
1.
0
plate (figure
65-5, view E).
figure 65-5
..3
Pass wire through hole in tailboom
O>>
top of plate of intermediate gearbox simulator,
T103224-101, around "V" groove in pin and
out through hole of forward (vertical) end
around gearbox mounting hole locations on
o-0
(CD
bulkhead alignment plate, T103225-119 and
(3) Adjust three leveling screws on
intermediate gearbox simulator T103224-101
amount approximately equal to thickness of
shim-stack established in step m(2) at
corresponding mounting bolt location.
E
tighten wire until all slack is removed and
secure end of wire. Secure end of wire with
tailboom.
65-00-00
Page 19
00)
L()
Rev. 5
BHT-212-MM
step m(7) and reinstall alignment wire in
accordance with steps k and I. Tighten
simulator mounting bolts 50 to 70 inch-lb.
CAUTIO'N
E°)
o-em0)o
2
(J1
(5.65 to 7.91 Nm) and confirm satisfactory
WHEN GEARBOX SIMULATOR
wire positions in holes in top and forward end
plates of simulator in accordance with step m.
If wire placement is satisfactory proceed to
MOUNTING BOLTS TO 20 TO 30
m(9) until satisfactory alignment is obtained.
TIGHTEN 4 SIMULATOR
QUO
T103224-101 IS SUPPORTED ON
ITS THREE LEVELING SCREWS.
3(n
step (10) otherwise repeat steps m(1) through
INCH- LB. (2.26 TO 3.39 Nm).
-p0
.-r
CYO
((S
of three levelling bolts until an acceptable
Clean shim contact areas on
tailboom using alphatic naphtha (C-305).
C-305
Apply a light coat of adhesive (C-317)
C-317 to
bottom surface of each of four shim-stacks.
..O
a)-
(5) Loosen or tighten each of four
simulator mounting bolts while adjusting each
(11)
r-O
c(0)
alignment wire in accordance with steps k.
and I. Ensure alignment wire is positioned in
"V" groove in simulator pin.
OT.
--h
and reinstall
(D'-'
n,-
o
i.
0.-
+''
accordance with step
(10) Loosen alignment wire and remove
intermediate gearbox simulator T103224-101.
Measure and record final thickness of shims
at each of four mounting bolt locations.
^"O
Install intermediate gearbox
simulator T103224-101 on tailboom in
(4)
Avoid placing adhesive within 0.25 inch (6.35
mm) of bolt holes.
simulator position is obtained. See step m.
Ensure simulator mounting bolts are
torqued to only 20 to 30 inch-lb. (2.26 to 3.39
(6)
(12) Install shim-stacks, adhesive side
down, in their original locations on tailboom.
Nm); then using a thickness gage, measure
and record gaps between lower surface of
NOTE
simulator and tailboom at each of the
Coat bottom surface of intermediate
gearbox simulator T103224-101 and
mounting bolt locations.
the threads and shank of each
Size thickness of shim-stacks for
simulator mounting bolt with a very
each simulator mounting bolt location equal to
the respective gaps measured in step m(6).
o'-'3
(7)
E
._r
light coat of petroleum jelly or
grease (C-001)
C-001 prior to installation.
minimum of 0.030 inch (0.762 mm) clearance
(14) Reinstall alignment wire in
accordance with steps k and I and confirm
exists between lower surfaces of gearbox
(other than the four mounting pads). If
to 70 inch-lb. ( 5.65 to 7.91 Nm). Do not
L(')
E
Install tail rotor gearbox using shim-stacks
manufactured in step m(7), then verify that a
'-F
(13) Reinstall intermediate gearbox
simulator and tighten four mounting bolts 50
(CS
(8) Loosen alignment wire and remove
intermediate gearbox simulator T103224-101.
Retract each of three leveling bolts so it does
not project below lower surface of simulator.
remove simulator until shim adhesive has set.
satisfactory wire positions in holes in top and
forward end plates of simulator in accordance
with step m.
exist, add equal amounts of shims at all four
mounting bolt locations as required to achieve
clearance required and repeat steps m(2) thru
this step except in step m(3) adjust simulator
leveling screws such that they project below
plate T103225-119 and thread wire through
forward and aft holes of a hanger simulator
mounting surface equal to total shim
thickness established above in this step.
Reinstall simulator in accordance
65-00-00
Page 20
Rev.5
,-r
Remove alignment wire from alignment
412-240-033-101.
Install hanger simulator 412-240-033101 at number four location on tailboom using
two AN4-10A bolts, two MS35650-3252 nuts
0.
OTC-
(9)
with step i using shim-stacks manufactured in
n.
'''
(J)
next step. If sufficient clearance does not
O(a
U.=
sufficient clearance exists, proceed directly to
and sufficient number of AN960-416L
BHT-212-MM
SEE DETAIL D
T 103226.101
0
SEE DETAIL B
0.020 WIRE
0
T103225-119
SEE DETAIL C
412.240-033.101
POSITION
T103224-101
POSITION
mm
m
m
f
BUSHING
T 103 225-117
.y
,,
,,.,,,
ALIGNMENT OF
TAlLB00M - MOUNTED
,,
,I lfl
HANGER BEARING
ASSEMBLIES
i'
.1
---
i
DETAIL D
DETAIL A
I
DETAIL C
DETAIL 6
m
2-
o
Z
coo
ACCEPTABLE WIRE
POSITION
UNACCEPTABLE
WIRE POSITION
0
DESIRED WIRE
POSITION
Om
0.020 WIRE
o.
0.005 MIN.
CLEARANCE
00
HOLE IN TOOL
DETAIL E
VIEW 6
212-M-65-5-1
o
o
o
Figure 65-5. Tail rotor driveshaft alignment (sheet 1 of 2}
65-00-00
Rev. 5
Page
21
BHT-212-M M
412-240-034-101 412-240:033-101
(SMALL HOLE)
0 . 020 WIRE /
HANGER
POSITION # 1
/
/
I
HANGER
POSITION #3
1
/`
412-240-035-101
(LARGE HOLE)
(USE ONLY AS WIRE
ANCHOR IN THIS
OPERATION)
VIEW C
ESTABLISHING PROPER
TAILBOOM POSITION
HANGER
POSITION #2
412.240-034-101
0.020 WIRE
POSITION #3
412-240-035-101
(LARGE HOLE)
i
ADJUSTABLE
SUPPORT
VIEW D
ALIGNMENT OF NO. 1
HANGER BEARING ASSEMBLY
T103226-101
T103225-119
0.020 WIRE
VIEW E
INTERMEDIATE GEARBOX
ALIGNMENT
Figure 65-5. Tail rotor driveshaft alignment (sheet 2)
65-00-00
Page 22
Rev. 5
212-M-65-5-2
B HT-212-M M
both forward mounting pads. Do the opposite
to adjust hanger simulator "pitch" aft. Install
four mounting bolts and verify acceptable
alignment in accordance with step r. It will
likely be necessary to perform step r(1) to
.ti
washers under nut to keep nut from bottoming
out in bolt grip, see detail B. Leave fasteners
slightly loose at this point.
Using uniform hand pressure on
p.
achieve acceptable "yaw" alignment.
while tightening the two bolts.
Tighten alignment wire in accordance
(3) If a "lateral position" error exists at
any hanger simulator (not simply a "yaw"
error) remove alignment wire and hanger
with steps k and I. Ensure alignment wire is
positioned in "V" groove in the intermediate
support to tail boom and remove support.
q.
0c0
extreme aft end of simulator, push hanger
simulator forward and hold in this position
simulator. Remove four bolts securing hanger
gearbox simulator T103224-101 pin.
Rework only the problem support in
Verify acceptable alignment of hanger
simulator 412-240-033-101 by confirming
rework, reinstall support. Reinstall hanger
simulator and alignment wire in accordance
alignment wire clears edges of holes in
forward and aft end plates of simulator by at
least 0.005 inch (0.127 mm), see view B.
(1)
Pluck wire and watch wire closely to see if the
wire continues to vibrate. If vibration
continues, wire clearance in holes is sufficient
with steps n thru q. Loosen four bolts slightly
and adjust lateral position of support so as to
<m'
w300
r.
figure 65-5
accordance with figure
65-5. Following
obtain satisfactory lateral alignment of
simulator. Verify acceptable alignment in
accordance with step r. It will likely be
necessary to perform step r (1) to restore
to proceed. Also verify alignment wire is in
acceptable positions in holes in forward and
acceptable "yaw" alignment.
follows:
each of four support mounting pads. Install
four mounting bolts and verify acceptable
hanger simulator alignment in accordance
with step r. It will likely be necessary to
.-.
(4) If hanger simulator position error is
in "elevation" (vertical position), remove four
bolts securing hanger support to tailboom and
add or remove same thickness of shims under
Q`/)
top end plates of intermediate gearbox
simulator T103224-101. If alignment of
hanger simulator is acceptable proceed
directly to step s; otherwise proceed as
0-0
-.,
2 CAUTION
perform step r(1) and (3) to achieve
acceptable "yaw" and "lateral position"
alignment. If lateral position is acceptable
proceed to step s.
DO NOT LOOSEN HANGER
WE-
SUPPORT TO AIRFRAME BOLTS
ONCE "YAW" ADJUSTMENTS
HAVE BEEN MADE.
171
securing hanger support to tailboom and shift
in intermediate gearbox simulator
pin in the following operations.
C\l
S.
Remove hanger simulator 412-240033-101 from number four hanger location
and install at location three. Perform steps o
,0..
a-.
support to obtain acceptable alignment.
Retighten bolts and verify acceptable
0)E
.(n
position error is in "yaw", loosen four bolts
Ensure alignment wire remains free
of kinks and is seated in "V" groove
-°0
If hanger simulator 412-240-033-101
(n:
(1)
NOTE
thru r.
E
alignment in accordance with step r.
(2) If hanger simulator error is in "pitch"
direction, remove four bolts securing hanger
D).
F--
support to tailboom. To adjust hanger
simulator "pitch" forward, add equal shims
under both aft support mounting pads and
(1) Loosen the alignment wire and
remove hanger simulator 412-240-033 from
remove same thickness of shims from under
hanger location three.
65-00-00
Rev. 5
Page 23
BHT-212-MM
NOTE
E
accordance with instructions given for 412340-033-101 hanger simulator in step o & p.
Hanger simulators 412-240-035 and
See view C.
412-240-034 are very similar in
appearance. Confirm the correct
m
NOTE
simulator is installed in the following
operation.
In steps w, x, and y, the 412-240-
035-101 hanger simulator at hanger
Install hanger simulator 412-240035-101 at hanger location two using two
AN4H7A bolts and a sufficient number of
AN960-416L washers to keep the bolts from
(LS
(2)
number one location is used as a
wire anchor. Alignment of the
number one hanger support is
accomplished per steps z thru ab.
bottoming out in the bolt grip. Leave fasteners
,-.
(Q.E
slightly loose at this point. Perform steps p
thru r, except, in step r the hanger simulator
...................
will be the 412-240-035-101.
../
CAUTION
Tail rotor driveshaft hanger assembly
t.
alignment on tailboom is now complete.
O07
DO NOT LOOSEN BOLTS
SECURING ANY HANGER
0G)
Remove tailboom bulkhead alignment plate
T103225-119, alignment wire, and hanger
SUPPORT TO TAILBOOM IN AN
simulator 412-240-035-101.
E F F O R T TO A C H I E V E
SATISFACTORY ALIGNMENT IN
Install tailboom on helicopter (Chapter
Chapter
U.
53).
53
STEPS W THROUGH AB.
W.
Install a length of unkinked 0.020 inch
diameter wire in accordance with steps j and
CAUTION
r00
m-1
THE FOLLOWING PROCEDURES
FOR ALIGNMENT OF HANGER
k. Route wire through each of three hanger
simulators. Tighten wire until all slack is
removed. Secure wire at forward end of
hanger simulator 421-240-034-101 at number
one hanger location. Secure end of wire with
BEARING ASSEMBLY AT HANGER
POSITION NUMBER ONE MUST BE
PERFORMED USING A TAILBOOM
safety-wire spinner pliers or other positive-
KNOWN TO HAVE ACCEPTABLE
NOTE
(J)
locking pliers.
TAIL ROTOR DRIVE SYSTEM
ALIGNMENT.
A stable cushion such as shot bags
or a sand bag should be placed
Install hanger simulators as follows:
between tailboom skin and support
so as to distribute the load and
W-_Q
V.
prevent damage to tailboom
Install hanger simulator 412-240034-101 at number two hanger location in
accordance with step s(2) for the 412-240(1)
cc)
structure. Tension on alignment wire
.'-
may require adjustment during
035-101 hanger simulator except perform only
referenced step p. See view C.
Esc
(2) Install hanger simulator 412-340033-101 at number three and number four
hanger locations in accordance with steps o &
p. See view C.
COO
..r
(3) Install hanger simulator 412-340035-101 at number one hanger position in
65-00-00
Page 24
Rev.5
tailboom positioning operation to
prevent wire sag.
Position an adjustable support under
tailboom. This support should be located at a
point approximately 12 inches (30.48 cm)
X.
forward of intermediate gearbox location
where extension of canted vertical fin spar
approaches adjacent tailboom bulkhead at
lower surface of tailboom, see view C. Slowly
BHT-212-MM
m-0
adjust elevation of support as required to
position alignment wire within acceptable
240-034-101 is acceptable proceed directly to
step ac; otherwise proceed as follows:
-0O
-,00
limits in each of three hanger simulators, see
view B. Once this position is obtained do not
NOTE
support until tail rotor drive system alignment
is complete.
Elongation of the four mounting
holes in the No. 1 hanger support is
not permitted.
((D
('-
(n-
reposition helicopter or readjust tailboom
y.
Remove alignment wire and hanger
simulator 412-240-035-101 from the number
(gyp
one hanger location. Reposition hanger
simulator 412-240-034-101 from number two
(1)
If hanger simulator error is in "yaw"
direction, loosen four bolts securing hanger
with step ab.
o
Of-
E
c
(2) If hanger simulator error is in "pitch"
position, relax tension on alignment wire and
remove four bolts securing hanger support to
airframe. To "pitch" hanger simulator forward
0'O
E
add equal shims under both aft support
U-0
with step s(2).
verify acceptable alignment in accordance
.-.
.4_
Remove hanger simulator 412-240033-101 from number four hanger location.
Install hanger simulator 412-240-035-101 at
number two hanger location in accordance
gearbox simulator T103224-101 pin.
O--0
:--O
(3) If hanger simulator error is in
"elevation" position (alignment wire hits top or
bottom of holes in hanger simulator at number
two hanger location), relax tension on
c
is seated in "V" groove in intermediate
alignment wire and verify acceptable hanger
simulator alignment in accordance with step
ab. It may be necessary to perform step ab(1)
to achieve acceptable "yaw" alignment.
3m3
a"_
positive-locking pliers. Ensure alignment wire
aft. Install four support mounting bolts, tighten
QC)
number one hanger location. Secure end of
wire with safety-wire spinner pliers or other
pads. Do just the opposite to "pitch" support
0
of hanger simulator 412-240-034-101 at
>a)
removed and secure wire at the forward end
E
at number three, two and one hanger
locations. Tighten wire until all slack is
shims from under both forward mounting
E
Install a new length of unkinked 0.020
inch diameter wire in accordance with steps j
and k. Route wire through hanger simulators
aa.
0.0
mounting pads and remove same thickness of
...
Z.
'-'
421-240-034-101 in accordance with steps o
and p, except use AN4-7A bolts. See view D.
O-0
forward fuselage. Install hanger simulator
support to airframe and shift support to obtain
acceptable alignment. Tighten four bolts and
hanger location to number one location on
0)
alignment wire and remove four bolts securing
hanger support to airframe. Add or remove
equal shim thickness under each of four
support mounting pads to obtain required
elevation. Install four mounting bolts and
NOTE
As an alternate procedure the
412-240-034-101 and tension/
necessary to repeat step ab(1) to achieve
E
verify acceptable hanger simulator alignment
EmNEE
alignment wire may be anchored at
in accordance with step ab. It may be
clamped at top end plate of
acceptable "yaw" alignment.
-.a
>,Q)
forward face of hanger simulator
intermediate gearbox simulator
Tail rotor drive system alignment is
CC.
complete. Remove all alignment tools and
W-0
T103224-101.
Verify acceptable alignment of
remaining on uppermost shim at intermediate
gearbox location.
are properly torqued. Remove any grease
((D
0).c
(SS
hanger location and in forward and top end
plates of intermediate gearbox simulator. See
view B. If alignment of hanger simulator 412-
(COD
plates of hanger simulators on tailboom, in aft
end plate of hanger simulator at number one
clears edges of holes in forward and aft end
'(D
tailboom support. Verify bolts securing hanger
supports to forward fuselage and to tailboom
bb.
yam
hanger simulator by confirming alignment wire
2.
Install tail rotor gearbox (paragraph
65paragraph 6558).
58
65-00-00
Rev. 5
Page 24A
B HT-212-M M
3.
Install intermediate gearbox (paragraph
paragraph
65-33).
65-33
Install tail rotor hangers and tail rotor
driveshafts (paragraphs
65-14 and 65-8).
paragraphs 65-14
65-8
65-00-00
Page 24B
Close and secure tail rotor driveshaft
covers.
(.0
4.
5.
Rev. 5
65-17. DELETED.
BHT-212-MM
INTERMEDIATE GEARBOX
65-18.
65-19. MAINTENANCE.
INTERMEDIATE (42°) GEARBOX.
J-0
The intermediate gearbox is installed on the
tailboom forward of the vertical fin. The
gearbox is aligned by use of shims between
still installed), removal, cleaning, limited
repair, and installation.
0m-
((DD
electrical chip detector and an oil level sight
gage are located on the right side. A vented
filler plug is installed on top of the case. Both
consists of troubleshooting, inspection (while
-ca
paragraph 65-16).
65-16
gearbox and tailboom (paragraph
An
The following maintenance procedures
the input and output quills have flexible,
NOTE
-4.
crown-toothed couplings for attachment of
driveshafts. A cover with cowl fasteners
0
When any doubt exists as to the
provides access to the gearbox.
serviceability of a gearbox, perform
serviceability checks defined
in
(fl
Chapter
63.
Chapter 63
65-20.
Troubleshooting.
Table 65-2. Troubleshooting - intermediate gearbox
INDICATION OF
TROUBLE
CHIP 42/90 BOX caution M e t a I
segment illuminated.
CORRECTIVE ACTION
PROBABLE CAUSE
chips
h a v e Remove and inspect electric
accumulated on chip
detector.
chip detector. If chips are found,
retain in a clean container for
subsequent investigation.
Faulty wiring or faulty chip Inspect wiring to chip detector
for continuity and grounding
detector.
(Chapter
98). Repair wiring or
Chapter 98
replace defective chip detector
as required.
o-0
Oil leakage from intermediate Faulty seals, packings, or Clean gearbox and recheck for
wear sleeves.
oil leak both static and dynamic
gearbox.
(engine operating). Measure
and record rate of leakage.
Maximum allowable static or
dynamic leakage at any single
O.0
source is two drops per minute.
Total allowable leakage from all
sources on gearbox is six drops
per minute.
FOR BEST VALUE, BUY GENUINE BELL PARTS
Rev.3
65-00-00
Page 25
BHT-212-MM
Table 65-2.
Troubleshooting - intermediate gearbox (Cont)
INDICATION OF
TROUBLE
PROBABLE CAUSE
CORRECTIVE ACTION
Replace gearbox seals,
packings, or wear sleeves if
maximum allowable leakage
rate is exceeded (BHT-212BHT-212CR&O).
CR&O
Cracked gearbox housing.
Inspection (installed).
65-21.
1.
Inspect gearbox for cracks in
housing. Replace gearbox if
cracks are found.
Cause of TEMP-PLATE discoloration shall be
determined and corrected prior to continued
paragraph 65-13
operation. Refer to paragraph
65-13 for
Open tail rotor driveshaft covers and
coupling TEMP-PLATE inspection.
remove intermediate gearbox cover.
Shake gearbox (9, figure
65-6) and check
figure 65-6
6.
Deleted.
for looseness on tailboom. No looseness is
acceptable.
7.
Inspect oil filler cap (paragraph
65-39).
paragraph 65-39
(OD
2.
Inspect oil sight glass for correct oil level.
Inspect sight glass and indicator for staining
cc)
which could be caused by movement of
'r-
212-CR&O).
212-CR&O
and/or cracks and crazing. Damage which
could cause oil leakage or make oil level
`i)
gearbox on tailboom. A gray residue is an
indication of fretting corrosion. If residue is
present, remove and inspect gearbox (BHTBHT-
u..
8.
3(Q
CO)
-ti
Check for evidence of fretting corrosion at
mating surface between gearbox and tailboom
3.
difficult to determine is not acceptable.
Inspect electrical chip detector for metal
particles. Refer to Chapter
63, Serviceability
Chapter 63
Checks if metal particles are found.
w=0
Inspection steps 4. through 10. are
not applicable if gearbox is removed
at step 3.
65-22.
SPECIAL TOOLS REQUIRED
and correct thread engagement.
Inspect couplings (8 and 10) for grease
leakage and for overheating evidenced by
5.
NUMBER
NOMENCLATURE
DB3703-30
Drain line
0
Off-
Jr..
Inspect four bolts (2) for correct torque
4.
Removal.
0
NOTE
370
9.
1.
overheat and /or component degradation.
replaced, unless conditions prevent operation,
perform a ten minute ground runup and drain
_q)
discoloration of temperature indicator TEMPPLATES (11) from white or light gray to black.
A change in color indicates a possible
65-00-00
Page 26
Rev.3
BUY BELL PARTS - BUY BELL VALUE
(3D
When intermediate gearbox is to be
BHT-212-MM
+..
o.-
operation oil using drain line DB3703-30. If
runup is not practical, remove intermediate
(42°) gearbox and flush with new lubricating
oil (Chapter
12) of same type being used in
Chapter 12
04-0
gearbox. Attach tag to intermediate gearbox
Inspection (removed from
helicopter).
65-24.
Refer to BHT-212-CR&O
BHT-212-CR&O manual.
-(a
stating: "PRESERVED WITH OPERATING
LUBRICANT."
65-25.
and
Inspection (special/conditional).
((DD
2. Open tail rotor driveshaft covers
remove intermediate gearbox cover.
(1 and 7,
Special/conditional inspections of
(Z(Do
:.-
3. Remove tail rotor driveshafts
figure
65-6) (paragraph
65-5).
figure 65-6
paragraph 65-5
NOTE
Remove chip detector (paragraph
65-34).
paragraph 65-34
5.
Remove four bolts (3).
intermediate gearbox are required
after tail rotor drive system
overtorque, sudden stoppage,
E
compressor stall, etc. (Chapter
Chapter 55).
(11
C11
4.
6. Remove gearbox (9). Inspect shims (6)
for secure installation on tailboom. If shims
65-26.
Repair.
r.-
(6) are not bonded to tailboom, index the
shims for installation in same location.
1.
LL)
65-23.
Repair intermediate gearbox (BHT-212BHT-212-
CR&O).
CR&O
Cleaning.
MATERIALS REQUIRED
2.
Repair faulty filler cap by same procedure
outlined for tail rotor gearbox filler cap
NOMENCLATURE
C-304
C-304
Solvent
3.
Clean gearbox with clean, lint-free cloth
0
1.
(paragraph
65-64).
paragraph 65-64
'^D)^
NUMBER
dampened with solvent (C-304).
C-304
Replace sight glass (3, figure
65-7) and/or
figure 65-7
indicator (4) that fails to pass inspection
(paragraph
65-31).
paragraph 65-31
Replace chip detector and/or self-closing
valve that fails to pass inspection (paragraph
paragraph
4.
CAUTION
65-35).
65-35
.................
00-70
00700
DO NOT FORCE SOLVENT AND/
OR DIRT INTO FLEXIBLE
COUPLING WHEN USING
COMPRESSED AIR.
2.
5.
Deleted.
65-27.
Installation.
Dry with filtered, compressed air.
MATERIALS REQUIRED
NUMBER
NOMENCLATURE
C-201
C-201
Primer
C-204
C-204
Primer
C-405
C-405
Lockwi re
GENUINE BELL PARTS ARE YOUR BEST VALUE
Rev.3
65-00-00
Page 27
BHT-212-MM
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Driveshaft
Bolt
Steel washer
Aluminum washer
Tailboom
Shim
Driveshaft
Coupling
Gearbox
Coupling
Temperature indicator
TEMP-PLATES
NOTE
Refer to BHT 212-CR&0 for TEMP-PLATES installation procedure.
212-M-65-6
Figure 65-6.
65-00-00
Page 28
Rev.3
Intermediate gearbox
FOR BEST VALUE, BUY GENUINE BELL PARTS
BHT-212-MM
NOTE
...................
?'CAUTIO'N
Complete driveshaft alignment and
gearbox shimming (paragraph
65paragraph 6516)
16 before proceeding with this step.
70z
PRIOR TO INSTALLATION OF
INTERMEDIATE (42) GEARBOX,
(PARAGRAPH
65-42).
PARAGRAPH 65-42
C3-
-on
ARE PROPERLY LUBRICATED
four bolts (2) with steel washers (3) next to
bolt head and aluminum washer (4) next to
gearbox. Bottoming of bolt grip is to be
determined as follows:
NOTE
00000
00000
Z)=
0
ROTATE FLEXIBLE COUPLING ON
INPUT QUILL AND CHECK FOR
One aluminum washer and one steel
washer is normally required at each
BINDING AND FOR EXISTENCE OF
BACKLASH BETWEEN PINION ON
0.-C3
-DC T.-
00Q)
ENSURE FLEXIBLE COUPLINGS
ON INPUT AND OUTPUT QUILLS
Position gearbox on tailboom and install
5.
()l
ACCOMPLISH THE FOLLOWING:
bolt location, however, additional
washers may be required at each
location if bolt grip bottoms in
INPUT QUILL AND GEAR ON
OUTPUT QUILL.
airframe prior to securing gearbox.
DRAIN OIL FROM GEARBOX AND
SERVICE WITH GEARBOX OIL
(CHAPTER
12).
CHAPTER 12
SHIMS (6, FIGURE
65-6) SHOULD
FIGURE 65-6
when above stated procedure is repeated.
S H I M S OF
After completion of bolt -grip-bottoming
test, retorque bolts 50 to 70 inch-Ibs. (5.7 to
5.9 Nm). Secure bolts in pairs at each side
with lockwire (C-405).
C-405 Additional washers (3)
may be required if bolt grip bottoms out on
O20=
SHOD
O_>_
070
Clean mating surfaces of gearbox (9,
figure
65-6) and tailboom (5).
figure 65-6
0.-
COMPONENTS.
a-0
FAILURE OF TAIL ROTOR DRIVE
b.
_O°
IDENTICAL
THICKNESS, ARE INSTALLED.
FAILURE TO COMPLY COULD
CAUSE MISALIGNMENT AND
,O-.
TAILBOOM, ENSURE SAME SHIMS
nom
looseness. If any of the washers are loose
add washers, as required at each bolt
location, to ensure no looseness is apparent
01-(n
BE BONDED TO TAILBOOM. IF
SHIMS ARE NOT BONDED TO
WHICH WERE REMOVED, OR
1.
Torque each bolt 30 to 40 inch-Ibs and
a.
check the washers under bolt heads for
nut plate.
6.
Install driveshafts (1 and 7) (paragraph
paragraph
65-15).
65-15
8.
Install chip detector (paragraph
paragraph 65-36).
65-36
Q0)
Position gearbox on tailboom.
.-.
2.
0_c
Verify actual presence of oil in sight gage
and check oil level to full mark on indicator.
7.
Connect wiring.
3.
Check gearbox for contact with shim (6)
If gearbox has not previously been
9.
installed. Maximum acceptable gap at any of
the four points is 0.001 inch (0.025 mm).
alternate run-in and test (paragraph
paragraph 65-28).
65-28
--o
(J1
3A)
10.
Install intermediate gearbox cover and
close tail rotor driveshaft covers.
0(a
Remove gearbox and coat all faying
11. Perform alternate run-in test (paragraph
paragraph
65-28).
65-28
E
surfaces, bolts, and bolt holes with unreduced
primer (C-201)
C-201 or primer (C-204).
C-204
qualified on run-in test stand, accomplish
0(D
4.
coo
at four points where bolts (2) are to be
65-00-00
Rev.5
Page 29
BHT-212-M M
Alternate run-in test.
leakage, remove couplings and replace
coy
65-28.
defective parts. Repeat test run.
NOTE
3=r
-..O
0
30-0
e000
am-
and/or component degradation. Cause of
discoloration shall be determined and
the event a run-in stand is not
available, the following functional
test may be accomplished as a
3Q.0
minimum acceptable alternate test.
O+_
(TS
corrected prior to continued operation. Refer
to paragraph
65-13 for inspection procedure.
paragraph 65-13
'O"'.
0«.
(DP)
black indicates a possible overheat condition
publication(s) furnished with run-in
stand for qualification for flight. In
a°.C
Q="0
((DD
i:3
and overheat condition. A change in color of
"TEMP-PLATES" from white or light gray to
and inspected in accordance with
fir
°:(Q
gearbox, after overhaul, be test run
0,('
14.
Check temperature indicator "TEMPPLATES" (1 1 , figure
65-6) for discoloration
figure 65-6
is desirable that intermediate
It
Install chip detector and fill gearbox to
specified level with approved lubricating oil
ELL
FM).
FM
Verify helicopter is properly serviced and
lubricated.
2.
,«-
15.
Install sufficient ballast in cabin to obtain
maximum allowable gross weight (BHT-212BHT-2121.
(Chapter
12).
Chapter 12
65-29.
SIGHT GLASS.
65-30.
Removal.
Start power sections (BHT-212-FM)
BHT-212-FM and
operate at 60% rpm for five minutes.
3.
Gradually increase rpm to 88% a rate of
7% each six minutes.
4.
SPECIAL TOOLS REQUIRED
NOMENCLATURE
5.
Hold at 88% for two minutes with
collective pitch applied to maximum which can
DB3703-30
Drain line
be maintained without becoming airborne, or
exceeding 100% torque.
1.
0.0
EEM
NUMBER
CO)
BHT-212-FM and
Shut down engine (BHT-212-FM)
0).
check electrical chip detector for foreign
material or chips.
drain.
BHT-212-FM and gradually
Start engine (BHT-212-FM)
increase to 88%. Run at 88% for six minutes.
8.
Apply collective pitch to maximum
4.
Remove glass (3) and packing (2).
5.
Remove indicator (4).
6.
Remove DB3703-30 drain line.
7.
Install chip detector (paragraph
65-36).
paragraph 65-36
Run at 100% rpm for 30 minutes with
can be maintained without becoming airborne
or exceeding 100% torque.
(<D
Inspection and repair.
Inspect sight glass for cracking and crazing.
Replace glass if cracked or if crazed or
discolored to the extent that accurate
^^C``
collective pitch in maximum up position which
65-31.
indication of oil level cannot be determined.
(CD
TO)
becoming airborne or exceeding 100% torque.
(t)
At a rate of 3% each six minutes,
gradually increase rpm to 100% without
10.
C,)
(TS
position which can be maintained without
becoming airborne or exceeding 100% torque.
11.
-I1
Remove ring (1, figure
65-7).
figure 65-7
E
9.
3.
(<D
Clean and install chip detector.
(ti
7.
Insert one end of DB3703-30 drain line
into container. Insert other end in hole where
detector was installed. Oil will automatically
2.
(J)
6.
Remove chip detector (paragraph
65-34).
paragraph 65-34
Installation.
Shut down engine (BHT-212-FM)
and
BHT-212-FM
drain oil from gearbox. Check gearbox oil and
65-32.
1.
Install indicator (4, figure
65-7).
figure 65-7
metal particles indicating internal failure.
2.
Install packing (2) on glass (3). Coat
3.
Install ring (1).
12.
chip detector for an excessive amount of
(TS
.-«
C'7
13. Inspect input and output quill couplings
and surrounding area for evidence of grease
leakage. If there is evidence of grease
65-00-00
Page 30
Rev. 5
packing (3) with oil used in gearbox (Chapter
Chapter
12).
12 Install glass (3) in gearbox port.
BHT-212-MM
1.
2.
3.
4.
5.
6.
Retaining ring
Packing
Sight glass
Oil level indicator
Gearbox
Cap assembly
212-M-65-7
Figure 65-7.
65-33.
Intermediate gearbox sight glass
disengage locking detent and withdraw
CHIP DETECTOR.
electrical chip detector (3) from self-closing
65-34.
valve (5). Inspect chip detector (3) for
presence of metal particles. If any metal
Removal.
particles are detected, refer to Chapter
63.
Chapter 63
SPECIAL TOOLS REQUIRED
NOTE
NUMBER
NOMENCLATURE
DB3703-30
Drain line
If self-closing valve (5) is to be
removed, install DB3703-30 oil
draining line in self-closing valve (5)
and allow oil to drain from gearbox.
NOTE
Electrical chip detector element (3,
figure
65-8) may be removed for
figure 65-8
inspection without draining gearbox
3.
Remove self-closing valve (5) from
gearbox (7). Remove gasket (6) from selfclosing valve (5). Discard gasket.
oil.
65-35.
Move nipple (8) back on electrical wire (2)
electrical wire (2).
2.
Press in on knurled body of electrical chip
,-.
detector (3), turn counterclockwise to
1. Inspect
65-9).
65-9
2.
chip detector for damage (figure
figure
(CD
0
N.-.
to expose nut (1). Remove nut (1) and
Repair of the electrical chip detector is
restricted to replacement of defective parts.
(OD
1.
Inspection and repair.
FOR BEST VALUE, BUY GENUINE BELL PARTS
Rev.3
65-00-00
Page 31
BHT-212-MM
65-36. Installation.
Inspection.
65-39.
MATERIALS REQUIRED
1. Inspect filler cap for distortion of pin (7,
figure
65-10) or other damage which would
figure 65-10
affect function.
NUMBER
NOMENCLATURE
C-405
C-405
Lockwire
NOTE
0D0
Some cap assemblies have a
stainless steel mesh plug installed
1. Lubricate new gasket (6, figure
figure 65-8)
65-8 with
instead of aluminum wool.
lubricating oil used in gearbox and install
The
spring-back check is not required for
these cap assemblies.
gasket on valve (5).
2.
Install self-closing valve (5) on gearbox
case (7). Torque valve (5) 120 to 150 in.lbs.
(14 to 17 Nm). Secure valve (5) to gearbox
case (7) with lockwire (C-405).
C-405
For cap assemblies with aluminum wool
installed, invert filler cap to expose washer
2.
(11). Press washer in to cap approximately
0.06 in. (1.5 mm) and release. Washer
should spring back against ring (12).
%
CAUTION
'
ENSURE PROPER PACKING (4) IS
INSTALLED ON CHIP DETECTOR
(3). THE WRONG PACKING MAY
NOT ALLOW CAUTION SEGMENT
TO ILLUMINATE AND MAY
RESTRICT OPERATION OF SELFCLOSING VALVE.
3.
Lubricate new packing (4) with lubricating
If
washer does not immediately spring back into
position aluminum wool packing (10) is dirty
or an insufficient amount is installed.
65-40.
Repair.
Repair intermediate gearbox filler cap
1.
assembly by same procedure outlined for tail
rotor gearbox filler cap (paragraph
65-64).
paragraph 65-64
65-41.
Installation.
oil used in gearbox and install packing on
chip detector (3). Insert chip detector (3) into
NOTE
(1t
valve (5). Push and twist clockwise to
engage locking detents.
Position nipple (8) over nut (1).
OIL FILLER CAP.
65-38.
Removal.
CA)
65-37.
(C)
2.
Unsnap pin (1) from gearbox (4).
0
twist clockwise to engage pin (7) in slots in
gearbox adapter.
2. Secure chain (3) to gearbox (4) with
safety pin (1).
65-42.
FLEXIBLE COUPLINGS.
65-43.
Lubrication.
(C)
Push down on cap (6, figure
65-10) and
figure 65-10
twist to disengage pin (7) from gearbox (4).
1.
1. Position cap assembly on gearbox (4,
figure
65-10). Push down on cap (6) and
figure 65-10
a'0
exceed 4 in.lbs. (0.45 Nm) torque on nut.
breather type.
(n'
Position electrical wire (2) on chip
detector (3) and install nut (1). Do not
4.
Ensure replacement cap is a
For lubrication of input and output flexible
couplings, refer to paragraph
65-14.
paragraph 65-14
65-00-00
Page 32
BHT-212-MM
Nut
Electrical wire terminal
Chip detector element
Packing
DETAIL A
Self-closing valve
Gasket
Intermediate gearbox
Nipple
Chip detector assembly
212-M-65-8
Figure 65-8. Chip detector
AREA
B
AREA
LIMITS
No cracks allowed.
A
Maximum depth of pitting is 0.030 inch (0.762 millimeter) with no more than
40 percent of any 1.0 inch (25.4 millimeters) square or 20 percent of total area
of any surface to be pitted.
B
Maximum depth of pitting is 0.020 inch (0.508 millimeter) with no more than
40 percent of any 1.0 inch (25.4 millimeters )square or 20 percent of total area
of any surface to be pitted. Thread damage is not permitted.
0.1
All
m°1
1.
2.
3.
4.
5.
6.
7.
8.
9.
.''
212-M-65-9
Figure 65-9.
Chip detector damage limits
GENUINE BELL PARTS ARE YOUR BEST VALUE
Rev.3
65-00-00
Page 33
B HT-212-M M
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
DETAIL A
Figure 65-10.
65-00-00
Page 34
Rev.3
Oil filler cap
FOR BEST VALUE, BUY GENUINE BELL PARTS
Safety pin
Packing
Chain
Gearbox
Ring
Cap
Pin
Spring assembly
Plug
Packing (aluminum wool)
Washer
Ring (spiralox)
212-M-65-10
BHT-212-MM
TAIL ROTOR GEARBOX
65-44.
TAIL ROTOR (90°) GEARBOX.
65-45. REMOVAL.
6.
Remove driveshaft (13) (paragraph
65-5).
paragraph 65-5
7.
Remove six nuts (11) with steel washers
(10).
8.
SPECIAL TOOLS REQUIRED
Remove gearbox (1) from support fitting
(14) using T101264-103 tailrotor gearbox
pusher (figure
figure 65-12).
65-12
NOMENCLATURE
DB3703-30
Drain line
NOTE
T101264-103
Pusher set
Install two spacers (15, figure 65-
c
NUMBER
1.
11), nut (11) with steel washer (10)
on gearbox studs (17) to hold input
quill in gearbox (1) while gearbox is
When tail rotor (90°) gearbox is to be
On-,,
replaced, unless conditions prevent operation,
perform a ten minute ground run. Drain
operating oil using DB3703-30 drain line. If
0-c3
0-c
run up is not practical, remove tail rotor
removed from helicopter.
Cleaning.
65-46.
gearbox and flush with new lubricating oil of
same type being used in gearbox. Attach tag
to tail rotor gearbox stating: "PRESERVED
2. Remove tail rotor
assembly (Chapter
64).
Chapter 64
hub and blade
070
1'.
and
NOMENCLATURE
C-304
C-304
Solvent
Clean gearbox with clean cloth dampened
in solvent (C-304).
C-304
1.
(0)
figure 65-11
3. Remove bolt (7, figure
65-11)
disconnect link (8) from lever (3).
NUMBER
5-d
4. Disconnect electrical wire and remove
chip detector (paragraph
65-57).
paragraph 65-57
((DD
070
OR DIRT INTO FLEXIBLE
COUPLING WHEN USING
COMPRESSED AIR.
CAUTION
.................
000
DO NOT IMMERSE GEARBOX IN
SOLVENT.
REMOVE CLAMP SET FROM BOTH
ENDS OF DRIVES HAFT (13)
BEFORE REMOVING EITHER END
0Z00=
OF SHAFT FROM CURVIC
COUPLINGS OR SUPPORT
UNATTACHED END OF SHAFT TO
HOLD SHAFT ALIGNED IN
00_70
DO NOT FORCE SOLVENT AND/
m
stn
Open vertical fin cover (12) and remove
intermediate gearbox fairing.
0W0
5.
CAUTION
.......
WITH OPERATING LUBRICANT".
MATERIALS REQUIRED
2.
Dry with filtered, compressed air.
65-47.
1.
Inspection (installed).
Open vertical fin cover (12, figure
65-11).
figure 65-11
NORMAL OPERATING POSITION
WHILE GEARBOX IS REMOVED.
65-00-00
Page 35
BHT-212-MM-7
2. Shake gearbox (1) and check for looseness on
tail rotor gearbox support fitting (14).
requiring special or conditional inspection (Chapter 5
and BHT-212-CR&O).
3. Inspect for evidence of fretting corrosion at
mating surface between gearbox (1) and tail rotor
gearbox support fitting (14), which could be caused by
movement of gearbox on support. A gray residue is an
indication of fretting-corrosion. If residue is present,
remove gearbox and inspect in accordance with
BHT-212-CR&O and inspect tail rotor gearbox support
fitting in accordance with Chapter 53.
65-49.
Repair
1. Polish out mechanical and corrosion damage
within limits (BHT-212-CR&O).
2.
Repair faulty oil filler cap (paragraph 65-61).
3.
Replace faulty sight glass (paragraph 65-52).
NOTE
Step 4 through step 9 are not applicable if
gearbox is removed at step 3.
Oil leaks shall not exceed two drops per
minute from any single source and shall not
exceed a total of six drops per minute from
all sources on gearbox.
4. Inspect gearbox for cracks and external damage,
oil leaks, and unserviceable fittings.
4. Replace chip detector and/or self-closing valve
that fails to pass inspection (paragraph 65-56).
5. Replace temperature indicator TEMP-PLATES
(Figure 65-11). Refer to BHT-212-CR&O for
installation procedures.
65-50.
INSTALLATION
MATERIALS REQUIRED
5. Inspect six nuts (11) for correct torque and correct
thread engagement (paragraph 65-50).
6. Inspect link assembly (8) and lever (3) for secure
installation.
7. Inspect coupling (16) for grease leakage and
outer coupling temperature indicator TEMP-PLATES
for discoloration and overheat condition. A change in
color of TEMP-PLATES (from white or light gray to
black) will indicate a possible overheat condition and/
or component degradation. The cause of discoloration
shall be determined prior to continued operation. Refer
to paragraph 65-13 for inspection procedure.
8. Inspect oil sight glass for correct oil level. Inspect
sight glass and indicator for damage and discoloration
(paragraph 65-54).
9. Inspect electrical chip detector for metal particles
and damage (paragraph 65-58). Refer to Chapter 63
for metal particle identification and required
maintenance actions.
65-48.
Inspection (Off Helicopter)
Inspect gearbox and historical records for evidence
gearbox has been involved in an accident or incident
65-00-00
Page 36
Rev. 10
18 SEP 2009
Refer to BHT-ALL-SPM for specifications.
NUMBER
NOMENCLATURE
C-204
Epoxy Polyamide
Primer
C-309
MEK
CAUTION
P RI O R T O I N S TA L LA T IO N O F TA I L
ROTOR GEARBOX, ACCOMPLISH THE
FOLLOWING:
ENSURE
GEARBOX
FLEXIBLE
COUPLING IS PROPERLY LUBRICATED
(PARAGRAPH 65-42).
ROTATE
FLEXIBLE
COUPLING
AND CHECK FOR BINDING AND
FOR EXISTENCE OF BACKLASH
BETWEEN
PINION
ON
INPUT
QUILL
AND GEAR
ON
OUTPUT
ECCN EAR99
BHT-212-MM
1.
NOTES
Q1
Q2
Shipping spacer is
removed from gearbox prior to
installation.
Refer to BHT-212-CR&0
for TEMP-PLATE
installation procedure.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Tail rotor gearbox
Cap assembly
Lever
Nut
Washer
Washer
Bolt
Link assembly
Cotter pin
Thin steel washer
Nut
Vertical fin cover
Driveshaft
Support fitting
Spacer (NAS43DD6-49)
(2)A,
Coupling
Stud
Temperature indicator
TEMP-PLATE
212-M-65-11
Figure 65-11. Tail rotor gearbox
FOR BEST VALUE, BUY GENUINE BELL PARTS
Rev.3
65-00-00
Page 37
BHT-212-MM
_..
N.0
Tail rotor gearbox pusher (T101264-103)
Adapter assembly (T101264-109)
Tail rotor gearbox assembly
Tail rotor gearbox support
Clamp assembly (T101264-107)
Screw Assembly (T101264-105)
Adapter retainer (T101264-121)
O.-
1.
7.000
2.
3.
4.
5.
6.
7.
NOTES
If not previously accomplished, thread screw assembly (6) into clamp assembly (5). Allow
sufficient clearance for positioning on support (4) and adapter assembly (2).
2.
Position both halves of adapter assembly (2) on tail rotor gearbox (3) against input quill as
shown.
3.
Position tail rotor gearbox pusher (1) on gearbox and support with hooks of clamp assembly
(5) centered securely over shoulders of support (4) and adapter retainer (7) over both halves
of adapter assembly (2).
4.
Tighten screw assembly (6) clockwise with a suitable wrench until tail rotor gearbox (3)
separates from support (4). Remove tools and lift gearbox from support.
c0"
1.
c/)
0
212-M-65-12
Figure 65-12. Tail rotor gearbox pusher T101264-103 tool application
65-00-00
Page 38
BHT-212-MM
6. Install six thin steel washers (10) and nuts
(11).
SHAFT.
LL.
DRAIN PRESERVATIVE OIL (IF
ANY) FROM GEARBOX AND
Torque nuts evenly in a star pattern 200
7.
SERVICE WITH GEARBOX OIL
to 235 in.lbs. (22.6 to 26.5 Nm). Repeat
torque pattern until all nuts retain torque
initially applied to first nut in pattern. Torque
value of first nut will decrease as other nuts
C_,
CHAPTER 12
(CHAPTER
12).
°'°o
Q(°
.0001-
Check mounting flange of gearbox (1,
N--
1.
c
figure 65-11
figure
65-11) for sealant protruding from the
three jackscrew holes. Trim off sealant flush
(using a sharp, non-metallic scraper) to allow
proper seating of tail rotor gearbox (1) flange
on support fitting (14).
E0--,
3'M
Q)0
Remove nuts (11), spacers (15), and
washers (10) from studs (17) around input
2.
are torqued.
Use a 0.005 in. (0.127 mm) feeler gage to
ensure no gap exists between gearbox input
quill and gearbox shim.
8.
Install driveshaft (13) (paragraph
65-8).
paragraph 65-8
9.
drive quill.
Using MEK (C-309)
and a non-metallic
C-309
Additional washers (5) may be used
0.-
to align nut (4) for cotter pin
installation.
Coat all faying surfaces of gearbox, studs,
NQ-
Install gearbox while primer is wet.
and one steel washer (5) under nut (4).
Install cotter pin (9).
Install chip detector (paragraph
65-60).
paragraph 65-60
11.
CAUTION
12. Verify actual presence of oil in sight
gage and check oil level to full mark on
(CD
.................
REQUIRED.
D03
ONLY, DO NOT INSTALL
15. If gearbox has not previously been
qualified on run-in test stand, accomplish
>A\\
(nab
0"W
SHIPPING SPACERS (15) ARE
FOR SHIPMENT OF GEARBOX
14. Install and rig tail rotor hub and blade
assembly and controls (Chapter
64 and 67).
Chapter 64
67
alternate run-in and test (paragraph
paragraph 65-51).
65-51
(CD
(n=()
OF STUDS. USE ADDITIONAL
THIN STEEL WASHERS (10) IF
Close vertical fin cover (12) and install
13.
intermediate gearbox fairing.
Dam:
2U)
z~zCC
NOT BOTTOM ON GRIP PORTION
indicator.
O-`
ENSURE A MINIMUM OF TWO
THREAD PITCHES, INCLUDING
CHAMFER, EXTEND THROUGH
NUTS (11). ENSURE NUTS DO
Z-lo
Connect link (8) to lever (3). Install bolt
(7) with one steel washer (6) under bolthead
10.
`-'U)
.-.
tailboom mount fitting, holes for studs in
C-204
mount and washers with primer (C-204).
='a
4.
'-F
S3)
and tailboom support fitting.
a-.
a-1
scraper, clean mating surfaces of gearbox
--.
3.
NOTE
SPACERS.
(77
65-51.
Alternate run-in test.
NOTE
Perform special inspection (Chapter
Chapter
5 after installation of tail rotor
5)
gearbox.
5. Position tail rotor gearbox (1) on support
fitting (14) with coupling (16) and studs (17)
through holes in support fitting (14).
NOTE
It is desirable that tail rotor gearbox,
after overhaul, be test run and
inspected in accordance with
publication(s) furnished with run-in
stand for qualification for flight. In
the event a run-in stand is not
65-00-00
Page 39
BHT-212-MM
3.
C
0-2
available, the following function test
Install ring (5).
7-0
may be accomplished as a mininum
acceptable alternate test.
gearbox per paragraph
65-28.
paragraph 65-28
()^
Perform alternate run-in test for tail rotor
4. Service
(Chapter
12).
Chapter 12
gearbox to specified level
65-56.
CHIP DETECTOR.
65-57.
Removal.
65-52. SIGHT GLASS.
Removal.
65-53.
SPECIAL TOOLS REQUIRED
SPECIAL TOOLS REQUIRED
NUMBER
NOMENCLATURE
DB3703-30
Drain line
NUMBER
NOMENCLATURE
DB3703-30
Drain line
NOTE
Remove chip detector (6,figure
figure 65-13)
65-13
1:r
1.
(paragraph
65-57).
paragraph 65-57
inspection without draining gearbox
Insert one end of DB3703-30 drain line
oil.
.'d
(DO
into container. Insert other end in hole where
detector was installed. Oil will automatically
drain.
CO)
2.
Electrical chip detector element (5,
figure
65-14) may be removed for
figure 65-14
1.
Move nipple (8) back on electrical wire (6)
.cam
to expose nut (7). Remove nut (7) and wire
(6).
CO)
E°-
4. Remove glass (4) and packing (3).
Discard packing.
5.
Remove indicator (2).
6.
Remove DB3703-30 drain line.
7.
Install chip detector (paragraph
65-60).
paragraph 65-60
2.
(5), turn counterclockwise to disengage
locking mechanism, and withdraw element (5)
from self-closing valve (3).
NOTE
If self-closing valve (3) is to be
removed, drain gearbox oil into
container with DB3703-30 drain line
installed in valve (3).
Inspection and repair.
65-54.
0L_
Inspect sight glass for crazing and
Inspect indicator for
discoloration.
O._
discoloration or any markings which would
impair determination of oil level. Replace
defective parts.
Installation.
65-55.
Press in on knurled body of chip detector
COQ
Remove ring (5).
E
C")
3.
3. Remove valve (3). Remove packing (2)
from valve (3). Discard packing.
65-58.
Inspection.
Inspect electrical chip detector element
(5, figure
65-14) for metal particles. Refer to
figure 65-14
Chapter
63 for metal particle determination
Chapter 63
and maintenance action required.
1.
Install indicator (2, figure
65-13)
figure 65-13
Install new packing (3) on glass (4). Coat
packing (3) with oil used in gearbox (Chapter
Chapter
12).
12
Install glass (4) in gearbox port.
65-00-00
Page 40
"44
NON
2.
?_0
(C)
1.
2. Inspect electrical chip detector
components for damage (figure
65-15).
figure 65-15
B HT-212-M M
1.
(11
('i
2.
3.
4.
5.
6.
Tail rotor gearbox
Oil level indicator
Packing
Sight glass
Retaining ring
Electrical chip detector
212-M-65-13
Figure 65-13.
65-59.
Sight glass
chip detector element (5). Insert element (5)
Repair.
4.
Position electrical wire (6) on element (5)
(T..
restricted to replacement of defective parts.
S11
Repair of the electrical chip detector is
U)1
into self-closing valve (3). Push down and
twist element until locking detents engage.
.-.
and install nut (7). Do not exceed 4 in.lbs.
(0.45 Nm) torque on nut. Position nipple (8)
65-60.
Installation.
over nut (7).
NUMBER
NOMENCLATURE
C-405
C-405
Lockwire
Lubricate new packing (2, figure
65-14)
figure 65-14
Q(7
++,
1.
111
Install self-closing valve (3) on gearbox
(1). Torque valve (3) 120 to 150 in.lbs. (14 to
17 Nm). Secure valve (3) to gearbox (1) with
lockwire (C-405).
C-405
2.
.-.
V.-
(?.
OIL FILLER CAP.
65-62.
Removal.
figure 65651. Push down on cap assembly (6, figure
16
16) and twist to disengage pin (7) from
gearbox (1).
2.
Unsnap safety pin (4) from gearbox (1).
_.0
Lubricate new packing (4) with lubricating
z-0
3.
65-61.
(OD
with lubricating oil used in gearbox and install
packing on self-closing valve (3).
Service gearbox to specified level with
approved lubricating oil if self-closing valve
(3) was removed (Chapter
12).
Chapter 12
5.
(J1
MATERIALS REQUIRED
S11
111
oil used in gearbox and install packing on
BUY BELL PARTS - BUY BELL VALUE
Rev.3
65-00-00
Page 41
1
BHT-212-MM
1.
2.
3.
Gearbox
Packing
Electrical chip detector self-closing valve
4.
Packing
5.
6.
7.
8.
Electrical chip detector element
Electrical wire
Nut
Nipple
Figure 65-14. Tail rotor gearbox electrical chip detector
65-63.
Inspection.
65-64.
212-M-65-14
Repair.
1. Inspect filler cap for distortion of pin (7,
figure
65-16) or other damage which would
figure 65-16
MATERIALS REQUIRED
'n.
affect function.
NOTE
Some cap assemblies have a
stainless steel mesh plug installed in
NUMBER
NOMENCLATURE
C-304
C-304
Solvent
C-422
C-422
Aluminum Wool
lieu of aluminum wool. The spring1.
installed.
aluminum wool packing (10, figure
65-16) as
figure 65-16
outlined in steps 2. through 10.
2.
Invert the filler cap to expose washer (9).
(=D
jai
2=w
Press washer approximately 0.06 in, (1.5
mm) and release. The washer should spring
3.
;(D
back against ring (8). If washer does not
spring back, aluminum wool packing (10) is
dirty or an insufficient amount is installed.
Repair is restricted to replacement of
0(a
c,.
back check is not required when
stainless steel mesh plug is
2.
Remove pin (7).
3.
Remove ring (5), cap (6), and spring
assembly (12) from plug (11).
4.
Remove ring (8) and washer (9).
5. If installed, remove aluminum wool
packing (10) and discard.
65-00-00
Page 42
Rev.3
GENUINE BELL PARTS ARE YOUR BEST VALUE
f<<
Clean parts with solvent (C-304).
C-304
(ma
6.
BHT-212-MM
AREA
B
AREA
ARFA
LIMITS
AREA
All
B
A
A
No cracks allowed.
A
Maximum depth of pitting is 0.030 inch (0.762 millimeter) with no more than
40 percent of any 1.0 inch (25.4 millimeters) square or 20 percent of total area
of any pitted surface.
B
Maximum depth of pitting is 0.020 inch (0.508 millimeter) with no more than
40 percent of any 1.0 inch (25.5 millimeters) square or 20 percent of total area
of any pitted surface. Thread damage is not permitted.
212-M-65-15
Figure 65-15. Tail rotor gearbox electrical chip detector damage limits
For filler caps which are filled with
aluminum wool, fill plug (11) with new
7.
aluminum wool (C-422)
C-422 until washer (9) will
spring back to original position after being
pressed in 0.06 in. (1.5 millimeters). Add or
twist clockwise to engage pin (7) in gearbox
adapter.
2.
Secure chain (2) to gearbox (1) with
safety pin (4).
remove aluminum wool as required.
8.
Install washer (9) and ring (8).
Ensure packing (3) is in place and install
spring assembly (12), cap (6), and ring (5) on
^CQ
((DD
9.
65-66. TAIL ROTOR GEARBOX FLEXIBLE
COUPLING.
65-67.
LUBRICATION.
plug (11).
-'O
65-65.
((DD
Insert pin (7) through cap (6). Bend end
of pin to secure.
10.
For lubrication of input flexible coupling, refer
to paragraph
65-14.
paragraph 65-14
Installation.
1. Position cap assembly on gearbox (1,
figure
65-16). Push down on cap (6) and
figure 65-16
65-00-00
Page 43
BHT-212-MM
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Gearbox
Chain
Packing
Safety pin
Ring
Cap
Pin
Ring (spiralox)
Washer
Packing (aluminum wool)
DETAIL A
212-M-65-16
Plug
Spring assembly
Figure 65-16. Tail rotor gearbox oil filler cap
65-00-00
Page 44
Rev.3
BUY BELL PARTS - BUY BELL VALUE