The clutch inspection chart (Fig. 8) outlines items
to be checked before and during clutch installation.
Use the chart as a check list to help avoid overlooking
potential problem sources during service operations.
The diagnosis charts describe common clutch problems,
causes and correction. Fault conditions are
listed at the top of each chart. Conditions, causes and
corrective action are outlined in the indicated columns.
The charts are provided as a convenient reference
when diagnosing faulty clutch operation.
CONDITION |
POSSIBLE CAUSES |
CORRECTION |
Disc facing worn out |
- Normal wear.
- Driver frequently rides (slips) the
clutch. Results in rapid overheating
and wear.
- Insufficient clutch cover
diaphragm spring tension.
|
- Replace cover and disc.
- Replace cover and disc.
- Replace cover and disc.
|
Clutch disc facing contaminated with
oil, grease, or clutch fluid. |
- Leak at rear main engine seal or
transmission input shaft seal.
- Excessive amount of grease
applied to the input shaft splines.
- Road splash, water entering
housing.
- Slave cylinder leaking.
|
- Replace appropriate seal.
- Remove grease and apply the
correct amount of grease.
- Replace clutch disc. Clean clutch
cover and reuse if in good condition.
- Replace hydraulic clutch linkage.
|
Clutch is running partially
disengaged |
- Release bearing sticking or
binding and does not return to the
normal running position.
|
- Verify failure. Replace the release
bearing and transmission front
bearing retainer as necessary.
|
Flywheel below minimum thickness
specification. |
- Improper flywheel machining.
Flywheel has excessive taper or
excessive material removal.
|
- Replace flywheel.
|
Clutch disc, cover and/or diaphragm
spring warped or distorted. |
- Rough handling. Impact bent
cover, spring, or disc.
- Improper bolt tightening
procedure.
|
- Replace disc or cover as
necessary.
- Tighten clutch cover using proper
procedure.
|
Facing on flywheel side of disc torn,
gouged, or worn. |
- Flywheel surface scored or
nicked.
- Clutch disc sticking or binding on
transmission input shaft.
|
- Correct surface condition if
possible. Replace flywheel and disc
as necessary.
- Inspect components and
correct/replace as necessary
|
Clutch disc facing burnt. Flywheel
and cover pressure plate surfaces
heavily glazed. |
- Frequent operation under high
loads or hard acceleration
conditions.
- Driver frequently rides (slips)
clutch. Results in rapid wear and
overheating of disc and cover.
|
- Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
- Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
|
Clutch disc binds on input shaft
splines. |
- Clutch disc hub splines damaged
during installation.
- Input shaft splines rough,
damaged, or corroded.
|
- Clean, smooth, and lubricate hub
splines if possible. Replace disc if
necessary.
- Clean, smooth, and lubricate
shaft splines if possible. Replace
input shaft if necessary.
|
Clutch disc rusted to flywheel and/or
pressure plate. |
- Clutch not used for and extended
period of time (e.g. long term
vehicle storage).
|
- Sand rusted surfaces with 180
grit sanding paper. Replace clutch
cover and flywheel if necessary.
|
Pilot bearing seized, loose, or rollers
are worn. |
- Bearing cocked during
installation.
- Bearing defective.
- Bearing not lubricated.
- Clutch misalignment.
|
- Install and lubricate a new
bearing.
- Install and lubricate a new
bearing.
- Install and lubricate a new
bearing.
- Inspect clutch and correct as
necessary. Install and lubricate a
new bearing.
|
Clutch will not disengage properly. 1 |
- Low clutch fluid level.
- Clutch cover loose.
- Clutch disc bent or distorted.
- Clutch cover diaphragm spring
bent or warped..
- Clutch disc installed backwards.
- Release fork bent or fork pivot
loose or damaged.
- Clutch master or slave cylinder
failure.
|
- Replace hydraulic linkage
assembly.
- Follow proper bolt tightening
procedure.
- Replace clutch disc.
- Replace clutch cover
- Remove and install clutch disc
correctly.
- Replace fork or pivot as
necessary.
- Replace hydraulic linkage
assembly.
|
Clutch pedal squeak. |
- Pivot pin loose.
- Master cylinder bushing not
lubricated.
- Pedal bushings worn out or
cracked.
|
- Tighten pivot pin if possible.
Replace clutch pedal if necessary.
- Lubricate master cylinder
bushing.
- Replace and lubricate bushings.
|
Clutch master or slave cylinder
plunger dragging andør binding |
- Master or slave cylinder
components worn or corroded.
|
- Replace clutch hydraulic linkage
assembly.
|
Release bearing is noisy. |
- Release bearing defective or
damaged.
|
- Replace release bearing.
|
Contact surface of release bearing
damaged. |
- Clutch cover incorrect or release
fingers bent or distorted.
- Release bearing defective or
damaged.
- Release bearing misaligned.
|
- Replace clutch cover and release
bearing.
- Replace the release bearing.
- Check and correct runout of
clutch components. Check front
bearing sleeve for damage/
alignment. Repair as necessary
|
Partial engagement of clutch disc.
One side of disc is worn and the
other side is glazed and lightly
worn. |
- Clutch pressure plate position
incorrect.
- Clutch cover, spring, or release
fingers bent or distorted.
- Clutch disc damaged or
distorted.
- Clutch misalignment.
|
- Replace clutch disc and cover.
- Replace clutch disc and cover.
- Replace clutch disc.
- Check alignment and runout of
flywheel, disc, pressure plate, andør
clutch housing. Correct as
necessary.
|