OBJECTIVES
After studying Chapter 6, the reader should be able to:
1. Discuss hydraulic principles.
2. Describe how a hydraulic system operates.
3. Identify the parts of a transmission hydraulic
system and explain their purpose.
4. Explain the requirements for a transmission
hydraulic system.
5. Identify the requirements for automatic
transmission fluid and the differences between
fluids.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
INTRODUCTION
• The automatic transmission’s hydraulic system has
several important functions .
• It must be able to:
– Apply the clutches and bands and therefore control the
transmission power flow,
– Transmit sufficient force and motion to completely apply
the control units to prevent slippage,
– Maintain fluid flow through the torque converter for its
proper operation,
– Maintain fluid flow to lubricate and cool the moving parts
of the gear train.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
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INTRODUCTION
FIGURE 6-1 A hydraulic diagram for a four-speed transmission with
electronic controls. Diagrams are used to determine the
relationship of the components. They are often color-coded to help
locate the circuits. (Courtesy of Chrysler Corporation)
Automatic Transmissions and Transaxles, Fourth Edition
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© 2010 Pearson Higher Education, Inc.
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HYDRAULIC PRINCIPLES
• Hydraulics, often called fluid power, is a method
of transmitting motion and/or force.
• Hydraulics is based on the fact that liquids can flow
easily through complicated paths, but they cannot
be compressed.
• All the components in a hydraulic system are
connected so that fluid pressure can be transmitted
and allowed to work.
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HYDRAULIC PRINCIPLES
FIGURE 6-2 Fluid pressure is transmitted undiminished
in all directions. Note that the pressure is equal
throughout the system.
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HYDRAULIC PRINCIPLES
FIGURE 6-3 Fluids flow freely and will assume the shape of their container (a), yet they are
virtually noncompressible (b).
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HYDRAULIC PRINCIPLES
• Pressure is defined as the
amount of force applied to
a given area.
FIGURE 6-4 A 100-lb force applied on an input
piston that has an area of 1 in. will produce a fluid
pressure of 100 psi.
Automatic Transmissions and Transaxles, Fourth Edition
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HYDRAULIC PRINCIPLES
FIGURE 6-5 System pressure can be determined by dividing the input
force (50 lb) by the area of the input piston (0.5 in2). Output force can be
determined by multiplying the area of the output piston (2 in2) by the fluid
pressure (100 psi).
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
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HYDRAULIC PRINCIPLES
• When discussing hydraulic pistons and computing
fluid pressures and forces, it is important to use the
area of the piston and not the diameter.
• The area of a piston or any circle can be
determined using this formula:
– πr2 or π (0.785d2)
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
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HYDRAULIC PRINCIPLES
FIGURE 6-6 A simple memory triangle will help you remember the commonly used
hydraulic formulas.
Automatic Transmissions and Transaxles, Fourth Edition
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SIMPLE HYDRAULIC SYSTEMS
• Many hydraulic systems
use an engine- or motordriven pump to produce
fluid movement.
• These systems normally
consist of the pump, a fluid
intake system usually
equipped with a filter, a fluid
supply (sump), control
valves, and the actuators
that provide the system
output.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
FIGURE 6-7 The basic components of a simple
hydraulic system.
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
• In most automatic
transmissions, the pump is
built into the front or engine
end of the transmission and
is driven by the back of the
torque converter.
FIGURE 6-8 In many transmissions, the oil pump is at
the front of the transmission and is driven by the torque
converter hub. (Courtesy of Chrysler Corporation)
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-9 This pump assembly (20) is attached to the valve body
(51) and channel plate (280). The pump is driven by the oil pump
drive shaft (340). (Courtesy of Slauson Transmission Parts,
www.slauson.com)
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-10 A pressure regulator valve. When fluid pressure acting on the right end
of the valve exceeds spring tension, the valve will move to the left and open the
passage back to the pump inlet. (Courtesy of Chryster Corporation).
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-11 This valve body has two sections that contain 11 sets of valves.
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-11 (CONTINUED) This valve body has two sections that contain 11 sets of valves.
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-12 The manual valve is connected to the gear shift lever
so movement of the lever will slide the valve along its bore. (Courtesy
of Nissan North America, Inc.)
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-13 A typical shift valve has a
spring to move the valve to a downshift
position; throttle pressure works with this
spring. When governor pressure gets high
enough, the valve will move to an upshift
position.
Automatic Transmissions and Transaxles, Fourth Edition
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BASIC AUTOMATIC TRANSMISSION HYDRAULICS
FIGURE 6-14 Operation of the valve
controls fluid flow to the actuator. It can
block operation (a), cause apply (b), or
cause release (c).
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PRODUCING FLUID FLOW AND PRESSURE
• Three common types of
rotary pumps are used to
produce the fluid flow and
resulting pressure in an
automatic transmission.
• They are the internalexternal gear with crescent
(crescent or gear) pump,
the gerotor (rotor) pump,
and the vane pump.
FIGURE 6-15 An internal-external gear pump (a),
gerotor pump (b), and vane pump (c).
Automatic Transmissions and Transaxles, Fourth Edition
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PRODUCING FLUID FLOW AND PRESSURE
FIGURE 6-15 (CONTINUED) An internal-external gear pump (a), gerotor pump (b), and vane pump (c).
Automatic Transmissions and Transaxles, Fourth Edition
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PRODUCING FLUID FLOW AND PRESSURE
FIGURE 6-16 As a pump rotates, a low
pressure/vacuum is created as the pumping
members move apart in one area, and
atmospheric pressure will force fluid into this
area. Pressure is created where the pumping
members move together.
Automatic Transmissions and Transaxles, Fourth Edition
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PRODUCING FLUID FLOW AND PRESSURE
FIGURE 6-17 A variable displacement vane pump in maximum and minimum output
positions. The slide is moved to the high-output position by the spring moving the
slide. Decreased pressure comes from the pressure regulator valve. (Reprinted with
permission of General Motors)
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PRODUCING FLUID FLOW AND PRESSURE
FIGURE 6-18 This transmission uses a dual-stage, external gear
pump. Both stages are used at low engine speeds to produce enough
fluid for the transmission’s needs. At higher engine speeds, the
secondary stage is vented. (Courtesy of Chrysler Corporation)
Automatic Transmissions and Transaxles, Fourth Edition
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PROVIDING CLEAN FLUID
• A filter is located at the pump inlet to trap dirt, metal,
and any other foreign particles that might cause
wear in the pump, bearings, bushings, and gear
train or cause sticking of the various valves.
• Three types of filters are used:
– Surface
– Depth
– Paper
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PROVIDING CLEAN FLUID
FIGURE 6-19 Two filters: a surface/screen
filter (a) and a depth/felt filter (b and c).
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PROVIDING CLEAN FLUID
FIGURE 6-20 A surface filter traps
particles that are too big to pass through
the openings in the screen. (Courtesy of
SPX Filtran)
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PROVIDING CLEAN FLUID
FIGURE 6-21 The surface area of a surface filter is reduced
somewhat by the material that makes up the screen. The size
of the screen openings determines how small of a particle
can be filtered.
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PROVIDING CLEAN FLUID
FIGURE 6-22 A depth filter is a group of
woven fibers of a certain thickness.
Foreign particles are trapped at different
levels as they try to flow through.
(Courtesy of SPX Filtran)
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PROVIDING CLEAN FLUID
FIGURE 6-23 Comparison of the filtering ability of four types of filters.
(Courtesy of SPX Filtran)
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PROVIDING CLEAN FLUID
FIGURE 6-24 General Motors transaxles have
two fluid reservoirs. One is the lower pan, and
one is the valve body cover. The thermostatic
element closes when the fluid heats up to raise
the fluid level in the upper pan. (Reprinted with
permission of General Motors)
Automatic Transmissions and Transaxles, Fourth Edition
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CONTROLLING FLUID FLOW
• The fluid flow from the pressure regulator valve to
the manual valve and into the control circuit is
called mainline, line, or control pressure.
• Flow to and from a transmission hydraulic actuator
is controlled by one or more valves.
• Spool valves sliding in a round bore are used for
this purpose.
• A spool valve gets its name from its resemblance to
a spool used for thread
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CONTROLLING FLUID FLOW
FIGURE 6-26 A spool valve and its bore. Note the
names of the various parts. (Courtesy of Chrysler
Corporation)
FIGURE 6-25 A spool valve resembles
a spool for thread (top).
Automatic Transmissions and Transaxles, Fourth Edition
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CONTROLLING FLUID FLOW
FIGURE 6-27 The sleeve allows the larger primary regulator valve to
enter its part of the bore and also provides the bore for the smaller No. 1
and No.2 plungers. (Courtesy of Toyota Motor Sales USA, Inc.)
Automatic Transmissions and Transaxles, Fourth Edition
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CONTROLLING FLUID FLOW
FIGURE 6-28 When a valve moves in its bore, the
side passages are opened or closed to control fluid
flow. (Courtesy of Chrysler Corporation)
Automatic Transmissions and Transaxles, Fourth Edition
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FIGURE 6-29 Fluid pressure acting on the surface
area of the valve face can move the valve along
the bore.
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CONTROLLING FLUID FLOW
FIGURE 6-30 The governor valve produces a fluid
pressure that is proportional to the speed of the
vehicle. (Courtesy of Nissan North America, Inc.)
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By Tom Birch and Chuck Rockwood
FIGURE 6-31 Ideally, governor pressure
increases with speed so the pressure in psi
matches the speed in mph. There should be
about 40 psi at 40 mph.
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CONTROLLING FLUID FLOW
FIGURE 6-32 A vacuum-operated throttle valve uses a vacuum modulator to produce an engine-load-sensitive
signal at the transmission (a). A mechanical-controlled throttle valve (in this case a cable) transfers an
engineload- sensitive signal through mechanical linkage (b). (Reprinted with permission of General Motors)
Automatic Transmissions and Transaxles, Fourth Edition
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CONTROLLING FLUID FLOW
FIGURE 6-33 This kickdown valve is controlled by the electric solenoid and is closed
when there is no electrical signal (a). The valve opens when the solenoid is energized
(b). (Courtesy of Nissan North America, Inc.)
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CONTROLLING FLUID FLOW
FIGURE 6-34 A check valve is opened by fluid flow
in one direction (left) and closes when the fluid tries
to flow in the other direction.
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FIGURE 6-35 When fluid flows through this shuttle
valve from port B to port C, the check ball moves
over to close port A (left). Fluid flow from port A will
close port B (right).
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CONTROLLING FLUID FLOW
FIGURE 6-36 A pressure relief valve (a). When fluid pressure acting on the area of
the ball exceeds the spring force, the ball will move off of its seat and allow excess
pressure to escape (b).
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CONTROLLING FLUID FLOW
• Valve Hydraulic Forces
– Think of a valve as a
hydraulic actuator.
– The hydraulic force exerted
by a valve is simply the valve
land area multiplied by fluid
pressure.
– The valve area is determined
using the formula for the area
of a circle, πr2.
FIGURE 6-37 This valve spool has four possible
hydraulic reaction faces. The areas are calculated like
those of any other circular surface using the formula
πr2.
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CONTROLLING FLUID PRESSURE
• Fluid pressure in an automatic transmission is
controlled by a variable pressure regulator valve.
• Fluid pressure must be high enough to apply a
clutch or band tightly enough to prevent slippage.
• Excessive fluid pressure will produce heat and fluid
foaming as well as more drag on the engine.
• Remember that fluid horsepower is a product of
pressure and flow.
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CONTROLLING FLUID PRESSURE
• In most transmissions, the pressure regulator valve
is positioned close to the outlet of the pump.
• This valve is usually arranged so fluid pressure is at
one end and a spring is at the other end.
• An additional passage from the pump enters the
valve at one valley, and a passage leading back to
the pump inlet is located at an adjacent valley
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CONTROLLING FLUID PRESSURE
FIGURE 6-38 When fluid pressure at the right end of the regulator valve gets high
enough, the valve will move toward the left and allow excess pressure to return to
the pump suction passage. (Courtesy of Chrysler Corporation)
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SEALING FLUID PRESSURE
• The fluid passages run throughout the valve body,
transmission case, shafts, and tubes of the
transmission.
• Remember that fluid transmits pressure equally
through a passage, regardless of its size or shape.
• The many passages in the valve body and the
transmission case look like a bunch of worm tracks
(a nickname used by transmission rebuilders.
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SEALING FLUID PRESSURE
FIGURE 6-39 This valve body uses upper (at bottom)
and lower sections (at top) that are separated by the
separator plate. Note how the separator plate can
restrict a passage so it becomes a port or orifice for
flow into the other section. (Courtesy of Chrysler
Corporation)
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SEALING FLUID PRESSURE
FIGURE 6-40 This intermediate shaft has fluid passages to transfer lubricating oil to
the planetary gearsets. (Courtesy of Chrysler Corporation)
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SEALING FLUID PRESSURE
FIGURE 6-41 Static seals prevent fluid from
passing between two stationary surfaces.
Dynamic seals keep fluid from passing through
when one of the surfaces is moving. (Courtesy of
Toyota Motor Sales USA, Inc.)
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SEALING FLUID PRESSURE
FIGURE 6-42 The sealing member of a metal-clad lip seal
makes a dynamic seal with the rotating shaft while the metal
case forms a static seal with the transmission case. (Courtesy
of Chrysler Corporation)
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SEALING FLUID PRESSURE
FIGURE 6-43 Sealing rings are used to seal the
passages between stationary and rotating members.
For example, the seal rings at the right keep the fluid
flows from the pump to the front clutch from escaping.
(Courtesy of Chrysler Corporation)
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SEALING FLUID PRESSURE
FIGURE 6-44 Fluid pressure forces a sealing ring outward in both
directions to make firm contact with the side of the groove and outer
diameter of the bore.
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SEALING FLUID PRESSURE
FIGURE 6-45 Metal seal rings (bottom)
have plain or hooked ends. Teflon rings
(top) are either uncut, scarf cut, or butt cut.
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SEALING FLUID PRESSURE
FIGURE 6-46 Clutch and servo piston seals are usually
O-rings, lathe-cut rings, or lip seals.
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SEALING FLUID PRESSURE
FIGURE 6-47 Two lip seals (blue) form fluidtight seals between the front clutch piston and
its bore. (Courtesy of Chrysler Corporation)
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SEALING FLUID PRESSURE
• Special Notes on Elastomers
– The rubber seal materials used for seals are called elastomers
because of their elastic nature.
– A dynamic seal must remain flexible and maintain its size and shape
in order to work properly.
– Plain rubber is not used in a transmission because it is adversely
affected by heat and contact with ATF.
– Natural rubber has an operating range of –58°F (–50°C) to 212°F
(100°C).
– Higher temperatures cause rubber materials to harden, and exposure
to transmission fluid causes it to swell excessively.
– A hardened seal may leak and cause a pressure loss, which in turn
will cause clutch slippage and failure.
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SEALING FLUID PRESSURE
FIGURE 6-48 This chart compares the ability of seal materials to withstand heat and
fluid.Note that natural rubber is very low in both cases.
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SEALING FLUID PRESSURE
FIGURE 6-49 The code letters cast into the surface of this seal identify the
manufacturer of the seal.
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APPLYING FLUID PRESSURE
• An automatic transmission shifts when hydraulic
pressure applies or releases a clutch or band.
• Hydraulic pressure causes the clutch or servo
piston to stroke, taking up the clearance, and then
squeezes the parts together.
• Both bands and clutches are released by spring
pressure.
• Band servos can also be released by hydraulic
pressure.
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APPLYING FLUID PRESSURE
FIGURE 6-50 A typical clutch piston area is
determined by subtracting the area of the
inner diameter from the area of the outercircle diameter.
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APPLYING FLUID PRESSURE
FIGURE 6-51 Some clutch pistons use a middle seal so
the piston will have two working areas.
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APPLYING FLUID PRESSURE
• Determining Piston Force
– The force exerted by a piston is simply the piston area
multiplied by fluid pressure.
– Like a valve, piston area is determined using the formula
πr2.
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MODIFYING FLOW AND PRESSURE
• During a shift , it is desirable to provide a gradual
pressure increase to the clutch pistons or band
servos.
• This improves the shift quality, producing the
desirable shift feel.
• Shift feel is a “seat-of-the-pants” response the driver
experiences during shifts.
• As the piston is stroking to take up the clutch or
band clearance, the pressures in the circuit are
relatively low.
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MODIFYING FLOW AND PRESSURE
• But the instant the clearance disappears and the
piston stops moving, the pressure rises very rapidly,
causing a sudden an possibly very harsh
application.
• Shift quality can be adjusted mechanically by
changing the friction material or hydraulically by
controlling fluid pressure.
• There are many variables that affect shift quality
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MODIFYING FLOW AND PRESSURE
FIGURE 6-52 Shift quality can be modified by changing any of these variables.
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MODIFYING FLOW AND PRESSURE
FIGURE 6-53 An orifice will cause a pressure
drop as fluid flows through (a); when the flow
stops, the pressure on both sides of the orifice
will be the same (b).
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MODIFYING FLOW AND PRESSURE
FIGURE 6-54 In neutral, the accumulator
piston is moved to the top of its stroke by line
pressure (top). Front servo apply pressure
strokes the accumulator piston downward,
delaying the pressure rise at the servo.
(Courtesy of Chrysler Corporation)
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MODIFYING FLOW AND PRESSURE
FIGURE 6-55 When a clutch applies, fluid pressure rises gradually until the circuit is filled and the piston
strokes to take up the clearance; then there is a rapid increase to line pressure (a). An accumulator can be
placed into the circuit to slow this pressure rise and soften clutch application (b).
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC TRANSMISSION FLUID
• Automatic transmission fluid (ATF) is one of the
most complex fluids used in a vehicle. It has to:
– Transfer hydrodynamic energy in the torque converter;
– Transfer hydrostatic energy at the clutch and servo
pistons as well as the valve body;
– Help transfer sliding friction energy as the clutches and
bands apply;
– Transfer excess heat away from high-temperature
locations such as the torque converter’s friction surfaces,
gears, and bushings;
– Lubricate the various moving parts.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC TRANSMISSION FLUID
FIGURE 6-56 The first special ATF was
developed in the late 1940s. Since that
date, advanced, special fluids have been
developed by domestic as well as foreign
vehicle manufacturers.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC TRANSMISSION FLUID
FIGURE 6-57 The markings on ATF containers show the fluid types. (b and c are courtesy of Pennzoil)
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC TRANSMISSION FLUID
FIGURE 6-58 The dynamic coefficient of friction for these two
fluids is almost the same, but the static friction is very different.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC TRANSMISSION FLUID
FIGURE 6-59 As the transmission warms up,
the fluid level increases from the cold mark at
70ºF to the hot mark at 180ºF.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SUMMARY
1. The hydraulic system applies the band and
clutches, transmits force and motion, maintains
fluid flow to the torque converter, and provides
lubrication and cooling to the moving parts of the
transmission.
2. Pumps produce the fluid flow in a transmission and
the restriction to the flow results in the system
pressure.
3. The mainline pressure is controlled by a variable
pressure regulator. Other valves and orifices are
used to modify mainline pressure for various
purposes.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SUMMARY
4. The flow of fluid through a transmission is
controlled by valves that are moved by hydraulic
pressure, spring force, centrifugal force, and
engine vacuum, electrically or manually.
5. Seals are used to confine the fluid to the
appropriate passages. Metal, rubber, Teflon, and
various synthetic materials are used for this
purpose.
6. Automatic transmission fluid is the lifeblood of an
automatic transmission, and only the specified fluid
should be used.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
REVIEW QUESTIONS
1.
2.
3.
4.
5.
6.
7.
The important functions of the automatic transmission’s hydraulic
system are to _________ the clutches and bands, transmit _________
and _________, maintain _________ _________ through the torque
converter, and cool and _________ the moving parts.
Pressure is defined as _________ pushing on a specified area and is
commonly measured in _________.
Hydraulic systems usually have a _________ valve or a _________
_________ to prevent damage from excessive pressure.
The automatic transmission pump turns whenever the _________ is
running.
Regulated pump output pressure is called _________ pressure.
Pump output volume changes relative to engine _________.
The main transmission filter is designed to trap _________, metal, and
other foreign _________.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
REVIEW QUESTIONS
8. A micron is approximately _________ of an inch.
9. The position of a valve can be controlled by: (List five)
10. Identify a transmission valve that is controlled
a. mechanically.
b. by centrifugal force.
c. by vacuum.
11. Older automatic transmissions use a _________ and a _________
_________ to control shift timing and quality.
12. Electronically controlled automatic transmissions use a _________
_________ _________ and a _________ _________ _________ to
help the ECU determine when the shift should occur.
13. A typical application for a ball check valve is to act as a _________
relief valve.
14. Three types of seals are used to seal clutch pistons. Which one
provides the best pressure retention?
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
REVIEW QUESTIONS
15. Clutches are applied by a _________ in the clutch
assembly and bands are applied by a _________ piston.
16. If a clutch piston has a diameter of 5 in. and 80 psi of
pressure is applied, the apply force is _________ pounds.
17. The rate that pressure is applied to a clutch will affect shift
_________ and shift _________.
18. Two devices that can be used to control shift feel and
quality are an _________ and an _________.
19. Driving conditions that produce higher temperatures are
_________ towing, driving up _________, and stop-and_________ driving.
20. Always use the automatic transmission fluid that is
recommended by the _________ when adding or replacing
the fluid.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
1. Fluid under pressure can be used to transmit
motion and force because
a) fluids cannot be compressed.
b) fluid conforms to the shape of its container.
c) fluids under pressure will apply pressure equally in all
directions.
d) All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
1. Fluid under pressure can be used to transmit
motion and force because
a) fluids cannot be compressed.
b) fluid conforms to the shape of its container.
c) fluids under pressure will apply pressure equally in all
directions.
d) All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
2. Student A says that fluid pressure is measured in
kilopascals or pounds per square inch. Student B
says that 1 psi is equal to about 7 kPa. Who is
correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
2. Student A says that fluid pressure is measured in
kilopascals or pounds per square inch. Student B
says that 1 psi is equal to about 7 kPa. Who is
correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. If a fluid pressure of 50 psi is exerted on a piston
area of 10 in2, it will generate a force of
_________ lb.
a)
b)
c)
d)
10
50
100
500
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. If a fluid pressure of 50 psi is exerted on a piston
area of 10 in2, it will generate a force of
_________ lb.
a)
b)
c)
d)
10
50
100
500
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Student A says that to increase hydraulic force, the
amount of fluid flow should be increased. Student
B says that to increase hydraulic force, the length
of the piston stroke should be increased. Who is
correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Student A says that to increase hydraulic force, the
amount of fluid flow should be increased. Student
B says that to increase hydraulic force, the length
of the piston stroke should be increased. Who is
correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. The pressure regulator valve
a)
b)
c)
d)
directs flow in the valve body.
regulates flow to match the driving conditions.
regulates pressure to match transmission requirements.
controls the pump speed.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. The pressure regulator valve
a)
b)
c)
d)
directs flow in the valve body.
regulates flow to match the driving conditions.
regulates pressure to match transmission requirements.
controls the pump speed.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. Positive displacement pumps
a)
b)
c)
d)
maintain a constant pressure.
move a constant volume of fluid.
vary the flow with rpm.
vary the flow with gear changes.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. Positive displacement pumps
a)
b)
c)
d)
maintain a constant pressure.
move a constant volume of fluid.
vary the flow with rpm.
vary the flow with gear changes.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. Fluid is forced through the pump intake by
a)
b)
c)
d)
pump suction.
inner case pressure.
atmospheric pressure.
gravity.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. Fluid is forced through the pump intake by
a)
b)
c)
d)
pump suction.
inner case pressure.
atmospheric pressure.
gravity.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. Student A says that some automatic transmissions
use an internal/ external pump. Student B says
that some automatic transmissions use gerotor or
a vane-type pump. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. Student A says that some automatic transmissions
use an internal/ external pump. Student B says
that some automatic transmissions use gerotor or
a vane-type pump. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Variable displacement pumps change the output
volume based on
a)
b)
c)
d)
torque converter demands.
transmission temperature.
gear range and shift demands.
engine speed.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Variable displacement pumps change the output
volume based on
a)
b)
c)
d)
torque converter demands.
transmission temperature.
gear range and shift demands.
engine speed.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. Student A says that a depth filter can trap smaller
particles than a surface filter. Student B says that
depth filter has more filter capacity than a surface
filter. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. Student A says that a depth filter can trap smaller
particles than a surface filter. Student B says that
depth filter has more filter capacity than a surface
filter. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
11. Excessive mainline pressure loss could be caused
by
a)
b)
c)
d)
too much fluid.
a plugged filter.
the wrong transmission fluid.
a plugged cooler line.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
11. Excessive mainline pressure loss could be caused
by
a)
b)
c)
d)
too much fluid.
a plugged filter.
the wrong transmission fluid.
a plugged cooler line.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
12. The part of a spool valve where pressure is
applied to cause the valve movement is called the
a)
b)
c)
d)
land.
bore.
valley.
face.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
12. The part of a spool valve where pressure is
applied to cause the valve movement is called the
a)
b)
c)
d)
land.
bore.
valley.
face.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
13. The throttle valve is designed to produce a fluid
pressure signal that is proportional to
a)
b)
c)
d)
the speed of the vehicle.
the gear selector position.
the load on the engine.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
13. The throttle valve is designed to produce a fluid
pressure signal that is proportional to
a)
b)
c)
d)
the speed of the vehicle.
the gear selector position.
the load on the engine.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
14. A governor’s output pressure increases gradually
and in proportion to
a)
b)
c)
d)
engine speed.
vehicle speed.
gear range.
road conditions.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
14. A governor’s output pressure increases gradually
and in proportion to
a)
b)
c)
d)
engine speed.
vehicle speed.
gear range.
road conditions.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
15. A shift valve is moved to the upshift position by
a)
b)
c)
d)
throttle valve pressure.
a spring.
governor pressure.
Any of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
15. A shift valve is moved to the upshift position by
a)
b)
c)
d)
throttle valve pressure.
a spring.
governor pressure.
Any of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
16. The metal balls are used in a valve body to
a)
b)
c)
d)
allow fluid flow in only one direction.
close one passage while fluid is flowing in another.
relieve excess pressure.
Any of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
16. The metal balls are used in a valve body to
a)
b)
c)
d)
allow fluid flow in only one direction.
close one passage while fluid is flowing in another.
relieve excess pressure.
Any of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
17. Student A says that an accumulator in a hydraulic
circuit is used to increase the fluid flow through the
circuit. Student B says that an accumulator in a
hydraulic circuit is used to cushion a shift by
absorbing some of the fluid flow. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
17. Student A says that an accumulator in a hydraulic
circuit is used to increase the fluid flow through the
circuit. Student B says that an accumulator in a
hydraulic circuit is used to cushion a shift by
absorbing some of the fluid flow. Who is correct?
a)
b)
c)
d)
Student A
Student B
Both A and B
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
18. An orifice in a fluid passage
a) reduces the pressure in a servo while it is in the applied
position.
b) causes a servo to apply faster than normal.
c) causes a pressure drop in the circuit while there is fluid
flow.
d) reduces the chance that a leak will develop.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
18. An orifice in a fluid passage
a) reduces the pressure in a servo while it is in the applied
position.
b) causes a servo to apply faster than normal.
c) causes a pressure drop in the circuit while there is fluid
flow.
d) reduces the chance that a leak will develop.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
19. Which type of seals require special tools to
properly install and resize?
a)
b)
c)
d)
Lip
O-ring
Teflon
square cut
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
19. Which type of seals require special tools to
properly install and resize?
a)
b)
c)
d)
Lip
O-ring
Teflon
square cut
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
20. Automatic transmission fluid contains additives
designed to
a)
b)
c)
d)
change the friction characteristics of the fluid.
clean the transmission.
reduce the rate of oxidation.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
20. Automatic transmission fluid contains additives
designed to
a)
b)
c)
d)
change the friction characteristics of the fluid.
clean the transmission.
reduce the rate of oxidation.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
21. Clutches are applied by hydraulic pressure and
released by
a)
b)
c)
d)
hydraulic pressure.
a spring.
centrifugal force.
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
21. Clutches are applied by hydraulic pressure and
released by
a)
b)
c)
d)
hydraulic pressure.
a spring.
centrifugal force.
Neither A nor B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
22. Bands are applied by hydraulic pressure and
released by
a)
b)
c)
d)
hydraulic pressure.
a spring.
centrifugal force.
Both A and B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
22. Bands are applied by hydraulic pressure and
released by
a)
b)
c)
d)
hydraulic pressure.
a spring.
centrifugal force.
Both A and B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
23. Student A says that all transmission fluids are the
same and a universal type of fluid can be used in
any automatic transmission. Student B says that
all transmission fluids are not the same and only
the fluid recommended by the manufacturer should
be used. Who is correct?
a)
b)
c)
d)
Student A
Student B
Neither A nor B
Both A and B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
23. Student A says that all transmission fluids are the
same and a universal type of fluid can be used in
any automatic transmission. Student B says that
all transmission fluids are not the same and only
the fluid recommended by the manufacturer should
be used. Who is correct?
a)
b)
c)
d)
Student A
Student B
Neither A nor B
Both A and B
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
24. When automatic transmission fluid is overheated,
a)
b)
c)
d)
it will turn pink.
nothing will happen.
varnish will form.
tar will form.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
24. When automatic transmission fluid is overheated,
a)
b)
c)
d)
it will turn pink.
nothing will happen.
varnish will form.
tar will form.
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
25. Using the wrong fluid could
a)
b)
c)
d)
shorten the life of the transmission.
cause shift-quality problems.
cause the clutches to slip excessively.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
25. Using the wrong fluid could
a)
b)
c)
d)
shorten the life of the transmission.
cause shift-quality problems.
cause the clutches to slip excessively.
All of these
Automatic Transmissions and Transaxles, Fourth Edition
By Tom Birch and Chuck Rockwood
© 2010 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458