WARNING
WARNING: EXERCISE CARE WHEN SERVICING
CLUTCH COMPONENTS. FACTORY INSTALLED
CLUTCH DISCS DO NOT CONTAIN ASBESTOS
FIBERS. DUST AND DIRT ON CLUTCH PARTS MAY
CONTAIN ASBESTOS FIBERS FROM AFTERMAR-
KET COMPONENTS. BREATHING EXCESSIVE CON-
CENTRATIONS OF THESE FIBERS CAN CAUSE
SERIOUS BODILY HARM. WEAR A RESPIRATOR
DURING SERVICE AND NEVER CLEAN CLUTCH
COMPONENTS WITH COMPRESSED AIR OR WITH
A DRY BRUSH. EITHER CLEAN THE COMPONENTS
WITH A WATER DAMPENED RAGS OR USE A VAC-
UUM CLEANER SPECIFICALLY DESIGNED FOR
REMOVING ASBESTOS FIBERS AND DUST. DO NOT
CREATE DUST BY SANDING A CLUTCH DISC.
REPLACE THE DISC IF THE FRICTION MATERIAL IS
DAMAGED OR CONTAMINATED. DISPOSE OF ALL
DUST AND DIRT CONTAINING ASBESTOS FIBERS
IN SEALED BAGS OR CONTAINERS. THIS WILL
HELP MINIMIZE EXPOSURE TO YOURSELF AND TO
OTHERS. FOLLOW ALL RECOMMENDED SAFETY
PRACTICES PRESCRIBED BY THE OCCUPATIONAL
SAFETY AND HEALTH ADMINISTRATION (OSHA)
AND THE ENVIRONMENTAL SAFETY AGENCY
(EPA), FOR THE HANDLING AND DISPOSAL OF
PRODUCTS CONTAINING ASBESTOS.
DIAGNOSIS AND TESTING - CLUTCH
ROAD TEST
Road test the vehicle and inspect components to
determine the clutch problem.
During a road test, drive the vehicle at normal
speeds. Shift the transmission through all gear
ranges and observe clutch action. If the clutch chat-
ters, grabs, slips or does not release properly, remove
and inspect the clutch components. If the problem is
noise or hard shifting further diagnosis may be
needed as the transmission or another driveline com-
ponent may be at fault.
CLUTCH CONTAMINATION
Clutch contamination can be caused by oil, water
or clutch fluid on the clutch disc and pressure plate
surfaces. This will cause chatter, slip and grab.
Inspect the clutch components and verify the contam-
inate.
Oil contamination indicates a leak at either the
rear main seal or transmission input shaft causing
an oil residue on the housing interior and clutch
cover and flywheel. Heat buildup caused by slippage
between the pressuer plate, disc and flywheel can
bake the oil residue onto the components. A glaze-
like residue ranges in color from amber to black wil
be noticed.
Road splash contamination, dirt/water can entering
the clutch housing due to loose bolts, housing cracks
or through hydraulic line openings. Driving through
deep water puddles can force water/road splash into
the housing through such openings.
IMPROPER RELEASE OR CLUTCH ENGAGEMENT
Clutch release or engagement problems are caused
by wear or damage to one or more clutch compo-
nents.
Release problems can result in hard shifting and
noise. Inspect the clutch cylinders/interconnecting
line, slave cylinder, release bearing, clutch disc, pres-
sure plate and release fork/pivot stud. Inpect these
components for loose, worn and damaged mounting
bolts or components.
Normal condensation in vehicles that are stored or
out of service for long periods of time can generate
enough corrosion to make the disc stick to the fly-
wheel, or pressure plate. If this condition is experi-
enced loosen the disc manually through the
inspection plate opening if equipped.
Engagement problems can result in slip, chatter/
shudder and noisy operation. Inspect the clutch disc
nad pressure plate for contamination, wear, misalign-
ment and distortion.
CLUTCH MISALIGNMENT
Clutch components must be in proper alignment
with the crankshaft and transmission input shaft.
Misalignment caused by excessive runout or warpage
of any clutch component will cause grab, chatter and
improper clutch release.
PRESSURE PLATE
Check pressure plate for flatness with a straight-
edge. Pressure plate friction area must be flat within
0.50 mm (0.020 in.). Attaching bolt holes should be in
contact with surface plate within 0.38 mm (0.015 in.).
Inspect friction faces of the flywheel and pressure
plate for:
• Flywheel Dowel Pin Fit
• Excessive Discoloration
• Burned Areas
• Small Cracks
• Deep Grooves
• Ridges
ZB CLUTCH 6 - 3
CLUTCH (Continued)
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