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very infrequently because the clutch cover and driven
plate are balanced as a unit during assembly. At this
time, the cover and plate are installed on the crank
shaft/flywheel assembly and given a final fine-tune bal
ance before installation in the vehicle.
Replacement of clutch components to correct vibra
tions should be performed only after exhausting all
other possibilities. Check clutch operation as follows.
(1) Raise vehicle on hoist and check engine front
support cushion interlocks for grounding. Repair as nec
essary. Check other engine components (e.g., exhaust
manifold, valve cover, etc.) for grounding on body or
frame. If one of these components is grounded, repair
and check for vibration. If vibration ceases, stop repair.
If vibration continues, lower vehicle and proceed to next
step.
(2) Disconnect accessory drive belts one at a time,
start engine, and check for vibration. If vibration stops
after removal of a drive belt, cause of vibration is re
lated to accessory driven by belt or by belt itself. Repair
as necessary. If vibration persists after checking all
belts and accessories, proceed to next step.
(3) Raise vehicle on hoist and remove transmission
and clutch housing. Refer to Clutch Removal.
(4) Support engine firmly.
(5) Check for loose flywheel mounting bolts.
Tighten bolts to 105 foot-pounds (142 N*m) torque if
necessary and operate engine. If vibration ceases, stop
repair. If vibration is still evident, proceed to next step.
(6) Check flywheel face runout while holding crank
shaft end play to zero. If runout is 0.005 inch (0.12 mm)
or less, proceed to next step. If runout exceeds 0.005 inch
(0.12 mm), replace flywheel and operate engine. If vibra
tion ceases, stop repair. If vibration is still evident,
proceed to next step.
(7) Check for damaged crankshaft vibration damp
ened If dampener is in good condition, proceed to next
step. If dampener is damaged, replace dampener and
operate engine. If vibration ceases, stop repair. If vibra
tion is still evident, proceed to next step.
(8) Check clutch cover imbalance as follows:
(a) Remove clutch cover and driven plate from
flywheel.
(b) Start and operate engine at speed where
vibration occurred.
(c) If vibration ceases, replace clutch cover and
recheck operation. If now OK, install clutch housing and
transmission. Refer to Clutch Installation.
(9) Lower vehicle.
Clutch Noises
T&rowoHt Bailing NoIm
Throwout bearing noises can be described as whirring,
grating, or grinding noises that occur when the clutch
pedal is depressed (clutch disengaged).
CLUTCH
2A-7
These noises usually continue until the clutch pedal is
fully released (clutch engaged) and the bearing is no
longer in contact with the clutch cover release levers.
Throwout bearing noise is corrected by replacing the
bearing as outlined in this chapter.
NOTE: The throwout bearing should not be replaced as
a matter of course when servicing the clutch cover or
driven plate. Replace the bearing only if defective.
Transmission Clutch Shaft or Countershaft Bearing Noise
Transmission clutch shaft or countershaft bearing
noises can be described as whirring, grating, or grinding
noises which cease when the clutch pedal is depressed
(clutch disengaged) or when the transmission is shifted
into gear. These noises are most noticeable when the
clutch pedal is fully released and the transmission is in
neutral. Correction of these noises will require trans
mission removal and replacement of the problem
bearing(s).
Crankshaft Pilot Bushing Noise
Pilot bushing noises can be described as squealing,
howling, or elephant-type trumpeting noises which are
most noticeable when the engine is cold. These noises
occur during the first few inches of clutch pedal travel
as the pedal is being released (partial clutch engage
ment) with the transmission in gear. It can also occur in
very cold weather when the pedal is fully depressed
(clutch disengaged) and the engine is started with the
transmission in neutral. To correct pilot bushing noise,
replace bushing as outlined in this section.
CLUTCH ADJUSTMENTS
Four-Cylinder CJ and Scrambler Models
The clutch hydraulic mechanism is self-adjusting.
Free play adjustments are not required nor is there any
provision for such an adjustment.
Six- and Eight-Cylinder Models
There are two clutch adjustments required: clutch
pedal free play and clutch cover release lever height.
Clutch pedal freeplay should be checked and adjusted
at the intervals specified in the Mechanical Maintenance
Schedule, Chapter B, or whenever diagnosis indicates
adjustment is needed. Refer to Clutch Pedal Free Play
Adjustment in this section.
Clutch cover release lever height should be checked
and adjusted whenever the cover is removed or replaced
during service operations, or whenever diagnosis in
dicates adjustment is needed. Refer to the Clutch Ser
vice—Six- and Eight-Cylinder Models section in this
chapter.
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Table of Contents
Troubleshooting
