CLUTCHES & MANUAL TRANSMISSIONS 7M-9
CLUTCHES
DIAPHRAGM SPRING CLUTCH
INDEX
Theory of Operation...................................................... 7M-9
Service Operations........................................................... 7M-13
Clutch................................................................................ 7M-9
Preliminary Inspection................................................. 7M-13
Clutch Components....................................................... 7M-9
Clutch Replacement...................................................... 7M-13
Clutch Operation........................................................... 7M-12
Diagnosis............................................................................. 7M-16
THEORY OF OPERATION
CLUTCH
Automotive clutches depend on friction for their
operation, whether it be solid friction as in the
conventional clutch, or fluid friction and inertia as
utilized in the fluid coupling and torque converter. The
fluid coupling serves the same purpose as the
conventional clutch, but the difference in the principle of
operation makes it necessary to discuss the two
mechanisms separately. Conventional clutches will be
discussed in this section.
A clutch in an automotive vehicle (Fig. 5) provides a
means of connecting and disconnecting the engine from
the power transmission system. Since the internal
combustion engine does not develop a high starting
torque, it must be disconnected from the power train and
allowed to operate without load until it develops enough
torque to overcome the inertial of the vehicle when
starting from rest. The application of the engine power
to the load must be gradual to provide smooth
engagement and to lessen the shock on the driving parts.
After engagement, the clutch must transmit all the
engine power to the transmission without slipping.
Further, it is desirable to disconnect the engine from the
power train during the time the gears in the transmission
are being shifted from one gear ration to another.
The transmission of power through the clutch is
accomplished by bringing one or more rotating drive
members secured to the crankshaft into gradual contact
with one or more driven members secured to the unit
being driven. These members are either stationary or
rotating at different speeds. Contact is established and
maintained by strong spring pressure controlled by the
driver through the clutch pedal and suitable linkage.- As
spring pressure increases, the friction increases:
therefore, when the pressure is light, the comparatively
small amount of friction between the members permits a
great deal of slippage. As the spring pressure increases,
less slippage occurs until, when the full spring pressure is
applied, the speed of the driving and driven members is
the same. All slipping has stopped and there is, in effect,
a direct connection between the driving and driven parts.
CLUTCH COMPONENTS
The principal parts of a clutch are: the driving members,
attached to the engine and turning with it; the driven
members attached to the transmission and turning with
it; the operating members which include the spring or
springs and the linkage required to apply and release the
pressure which holds the driving and driven members in
contact with each other. Figure 6 shows a clutch cutaway
so operating members can be seen.
Driving Members
The driving members of a clutch usually consist of two
nodular iron plates or flat surfaces machined and ground
to a smooth finish. Nodular iron is desirable because it
contains enough graphite to provide some lubrication
when the driving member is slipping during engage
ment. One of these surfaces is usually the rear face of
the engine flywheel, and the other is a comparatively
heavy flat ring with one side machined and surface. This
part is known as the pressure plate. It is fitted into a steel
cover, which also contains some of the operating
members, and is bolted to the flywheel.
Driven Members
The driven member is a disc with a splined hub which is
free to slide lengthwise along the splines of the clutch
shaft, but which drives the shaft through these same
splines.,Grooves on both sides of the clutch driven plate
lining prevent sticking of the plate to the flywheel and
pressure plate due to vacuum between the members on
disengaging. The clutch driven plate (Fig. 7) is usually
made of spring steel in the shape of a single flat disc
consisting of a number of flat segments. Suitable
frictional facings are attached to each side of the plate
by means of brass rivets. These facings must be heat
resistant since friction produces heat. The most
commonly used facings are made of cotton and asbestos
fibers woven or molded together and impregnated with
resins or similar binding agents. Very often, copper wires
are woven or pressed into material to give it additional
strength.
LIGHT DUTY TRUCK SERVICE MANUAL
Summary of Contents for Light Duty Truck 1973
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Page 53: ...HEATER AND AIR CONDITIONING 1A 27 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 115: ...LIGHT DUTY TRUCK SERVICE M A N U A L HEATER AND AIR CONDITIONING 1A 89...
Page 123: ...BODY 1B 3 Fig 6 Typical 06 Van LIGHT DUTY TRUCK SERVICE MANUAL...
Page 149: ...BODY 1B 29 Fig 84 Body Mounting 06 Fig 85 Body Mounting 14 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 171: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 2 Frame Horizontal Checking Typical FRAME 2 3...
Page 173: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 4 10 30 Series Truck Frame FRAME 2 5...
Page 174: ...2 6 FRAME LIGHT DUTY TRUCK SERVICE MANUAL Fig 5 Underbody Reference Points G Van...
Page 185: ...FRONT SUSPENSION 3 11 Fig 16 Toe out on Turns LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 351: ...ENGINE 6 15 Fig ID Sectional View of Eight Cylinder Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Page 375: ...EN G IN E 6 39 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 376: ...6 4 0 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 377: ...ENG IN E 6 41 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 378: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 37L K Series Engine Front Mount 6 42 ENG INE...
Page 400: ...6 6 4 ENG INE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 401: ...ENG IN E 6 65 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 402: ...6 6 6 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 403: ...E NG IN E 6 67 Fig 36V C Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 423: ...EN G IN E C OOLING 6K 13 Fig 16 Overheating Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 424: ...6 K 1 4 ENG INE COOLING Fig 17 Coolant Loss Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 456: ...6M 32 ENGINE FUEL Fig K15 Accelerator Controls G Van L 6 LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 512: ...Fig 18e Vacuum Advance Diagram V8 Engine...
Page 516: ...6 T 2 4 E M IS S IO N CONTROL SYSTEMS LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 593: ...CLUTCHES MANUAL TRANSMISSIONS 7M 3 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 598: ...7M 8 CLUTCHES MANUAL TRANSMISSIONS LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 743: ...FUEL TANKS AND EXHAUST 8 13 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 744: ...8 14 FUEL TANKS AND EXHAUST LIGHT DUTY TRUCK SERVICE MANUAL...
Page 760: ...8 30 FUEL TANKS AND EXHAUST Fig 40 Exhaust Pipe P Models LIGHT DUTY TRUCK SERVICE MANUAL...
Page 761: ...FUEL TANKS AND EXHAUST 8 31 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 763: ...FUEL TANKS AND EXHAUST 8 33 LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 832: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 106 Power Steering Pump Mounting Typical 9 66 STEERING...
Page 833: ...PUMP ASSEMBLY STEERING GEAR TYPICAL SMALL V8 TYPICAL LARGE V8 STEERING 9 67...
Page 861: ...STEERING 9 95 Fig 134 Power Steering Pump Leakage LIGHT DUTY TRUCK SERVICE MANUAL...
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Page 886: ...11 10 CHASSIS SHEET METAL LIGHT DUTY TRUCK SERVICE MANUAL...
Page 891: ...ELECTRICAL BODY AND CHASSIS 12 5 LIGHT DUTY TRUCK SERVICE MANUAL...
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