CLUTCH DISC
Clutch disc runout should not exceed 0.5 mm
(0.020 in.). Check runout 6 mm (0.25 in.) from the
outer edge of the disc. Replace clutch disc if the worn
within 0.38 mm (0.015 in.) of the rivet heads. Inspect
clutch disc for:
• Discoloration
• Burned Areas
• Cracks
• Worn Disc Hub Splines
• Broken Springs
• Lose Rivets
• Oil Soaked
DIAGNOSIS CHART
The diagnosis charts Diagnosis Chart describe
common clutch problems, possible causes and correc-
tion.
DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
Disc facing worn out 1. Normal wear. 1. Replace pressure plate and disc.
2. Driver frequently rides (slips) the
clutch. Results in rapid overheating
and wear.
2. Replace pressure plate and disc.
3. Insufficient pressure plate
diaphragm spring tension.
3. Replace pressure plate and disc.
Clutch disc facing contaminated with
oil, grease, or clutch fluid.
1. Leak at rear main engine seal or
transmission input shaft seal.
1. Replace appropriate seal.
2. Excessive amount of grease
applied to the input shaft splines.
2. Remove grease and apply the
correct amount of grease.
3. Road splash, water entering
housing.
3. Replace clutch disc. Clean
pressure plate and reuse if in good
condition.
4. Slave cylinder leaking. 4. Replace hydraulic clutch linkage.
Clutch is running partially
disengaged.
1. Release bearing sticking or
binding and does not return to the
normal running position.
1. Verify failure. Replace the release
bearing and transmission front
bearing retainer as necessary.
Flywheel below minimum thickness
specification.
1. Improper flywheel machining.
Flywheel has excessive taper or
excessive material removal.
1. Replace flywheel.
Pressure plate or diaphragm spring
warped or distorted.
1. Rough handling. Impact bent
cover, spring, or disc.
1. Replace disc and pressure plate
as necessary.
2. Improper bolt tightening
procedure.
2. Tighten clutch cover using proper
procedure.
Facing on flywheel side of disc torn,
gouged, or worn.
1. Flywheel surface scored or
nicked.
1. Correct surface condition if
possible. Replace flywheel and disc
as necessary.
2. Clutch disc sticking or binding on
transmission input shaft.
2. Inspect components and
correct/replace as necessary.
6 - 4 CLUTCH ZB
CLUTCH (Continued)
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