Introduction
This chapter explains how to diagnose and service
clutches. Clutch problems and their causes are identified.
Procedures performed with the clutch in place, such as
clutch adjustment, are covered. Major repair and replace-
ment procedures, which require clutch removal, are also
explained.
Clutch Problems and
Troubleshooting
You cannot properly service a clutch until you
know what is wrong with it. In many instances, a clutch
problem that seems to be severe is minor and easily
remedied. In other cases, the solution involves replacing
the clutch assembly or some other major component.
Check the easiest, most obvious solutions (such as
clutch adjustment) before removing the clutch. Also,
look beyond the clutch for possible solutions. Consider
the possibility the problem is something other than the
clutch. Figure 7-1 shows typical clutch problems. Study
them carefully.
Clutch discs are like brake linings: they gradually
wear out as they operate. Every time the clutch is engaged
or disengaged, some friction material is removed from the
clutch disc. The amount of material lost during each action
is small, and most clutches will last for 50,000 miles
(80,000 km) or more. It is normal for a clutch to wear out
after this mileage is reached.
Often, however, a clutch will not last as long as
50,000 miles. Like any other mechanical part, the clutch
can be damaged by careless or abusive operation. Further,
it can be damaged by outside factors—factors that cannot
be attributed to the vehicle operator. It is important for
126 Manual Drive Trains and Axles
Clutch disc
facing
worn
Engine flywheel
friction surface
warped or damaged
Leaking rear main
bearing seal
Clutch
pilot
bearing
worn
Flywheel attaching bolts
stripped or broken
Clutch release
bearing
dry or worn
Bearing collar
unlubricated
Clutch housing
misalignment
or damaged
Transmission
input shaft
damage or wear
Leaking front
bearing retainer
seal
Clutch
fork bent
Front bearing
retainer hub
dry or worn
Release levers or
fingers bent or worn
Clutch pressure
plate damaged
or worn
Loose, broken, or
missing clutch cover
attaching bolts
Figure 7-1. Note typical problems with the clutch assembly. Some defective parts, such as a leaking engine oil seal, are not part of
the clutch assembly but can cause clutch problems. It is very unusual for only one part of a clutch to wear out. You should usually
replace any clutch part that you suspect is bad. (DaimlerChrysler)