Content .. 1254 1255 1256 1257 ..
Chevrolet Silverado / GMC Sierra. Manual - part 1256
Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.
Inspect the clutch master cylinder for the correct fluid level.
Inspect the hydraulic clutch lines for dents, kinks, or other obvious damage that may affect
the clutch system operations.
Inspect the clutch system for contamination of dirt, oil, or other substances that may affect
the clutch system operations.
Inspect for aftermarket components and power take-off (PTO) set-ups.
Intermittent
Test the vehicle under the same conditions that the customer reported in order to verify the system
is operating properly.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:
Clutch Drag Hard Shifting
Clutch Slipping
Clutch Grabbing
Clutch Rattle
Clutch Noisy
Clutch Pedal Spongy Low Pedal Effort
Clutch Pedal Hard to Push
Clutch Vibration
CLUTCH DRAG HARD SHIFTING
IMPORTANT: Due to the variety of clutch options there may be components in
the mechanical diagnostic tables that are not on a particular
vehicle.
Cause
Action
DEFINITION: The clutch does not disengage completely to allow smooth shift operations.
It may cause gear clashing while the vehicle is not moving, at idle, and shifting out of
neutral, or hard shifting in and out of gears while driving the vehicle.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Clutch - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Review the Symptoms - Clutch and perform the necessary inspections.
Pedal blocked from full travel
1. Inspect for obstacles that prevent the
pedal from going to the floor.
2. Clear any obstacles from under the pedal
area, such as floor mats, damaged floor,
or interior panels.
Too much travel between pedal and clutch
master cylinder
1. Inspect the pedal for worn bushings.
2. Replace the pedal bushings if worn.
Refer to Clutch Pedal Replacement.
Clutch pedal mounting loose
1. Inspect the clutch pedal mounting
bracket for loose or missing fasteners.
2. Replace or repair the fasteners. Refer to
Clutch Pedal Replacement.
Linkage at pedal worn or damaged
1. Inspect the linkage at the pedal for
excessive wear.
2. Repair or replace the linkage as
required. Refer to Clutch Pedal
Replacement.
Clutch master cylinder seized or binding
1. Inspect the master cylinder for the piston
being able to move freely and full range
of travel.
2. Replace the clutch master cylinder as
required. Refer to Clutch Master
Cylinder Replacement.
Air in the clutch hydraulic system
Bleed the clutch hydraulic system. Refer to
Hydraulic Clutch Bleeding.
Clutch actuator cylinder seized or binding
1. Inspect the clutch actuator piston for
moving freely.
2. Replace the clutch actuator cylinder if
the piston is binding. Refer to Clutch
Actuator Cylinder Replacement
(TZ0) or Clutch Actuator Cylinder
Replacement (M96).
Clutch master cylinder leaking internally
1. Inspect for proper pedal reserve. Refer
to Clutch System Description and
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Clutch - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Operation.
1. Let up halfway on pedal.
2. Apply the pedal a few times and
hold down for 30 seconds.
3. Inspect to ensure there is still the
proper pedal reserve, without
letting pedal fully up.
2. Replace the clutch master cylinder if it
will not hold pedal reserve. Refer to
Clutch Master Cylinder
Replacement.
Damaged clutch assembly components
1. Remove the clutch assembly.
2. Inspect the following clutch assembly
components for damage:
Damaged clutch disc hub splines
Bent clutch disc
Bent drive straps
Broken or warped pressure plate
3. Replace the clutch assembly if any of the
above damage is found. Refer to Clutch
Assembly Replacement.
Excessive side loading on the release bearing
1. Inspect the following clutch system
components:
Worn or damaged pilot bearing
Excessive flywheel runout
Excessive engine to transmission
misalignment
Clutch actuator cylinder mounting
surface out of alignment
2. Repair or replace any faulty
components.
Faulty pilot bearing
Replace the pilot bearing. Refer to Clutch
Pilot Bearing Replacement.
Transmission input shaft splines worn or
damaged
Replace the transmission input shaft. Refer to
Transmission Disassemble for the Tremec
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Clutch - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
CLUTCH SLIPPING
5-Speed (M96) or Transmission
Disassemble for the Tremec 5-Speed (TZO).
Tight or contaminated clutch disc splines
1. Clean the clutch disc and input shaft
splines.
2. If the clutch disc will not clean, replace
the clutch assembly. Refer to Clutch
Assembly Replacement.
Flywheel housing, engine block to clutch
housing, or transmission front case
excessively misaligned
1. Inspect the clutch housing or the
transmission front case for being faulty.
2. Replace the clutch housing if it is faulty.
Refer to Transmission Replacement
for the Tremec 5-Speed (M96) or
Transmission Replacement for the
Tremec 5-Speed (TZO).
3. Replace the transmission front case half.
Refer to Transmission Disassemble
for the Tremec 5-Speed (M96) or
Transmission Disassemble for the
Tremec 5-Speed (TZO).
Grease or oil contamination on the clutch
discs facing
1. Repair the oil leak.
2. Repair the grease leak.
3. Clean the clutch disc facing and the
other clutch assembly components.
4. Replace the clutch assembly if it will not
clean. Refer to Clutch Assembly
Replacement.
Cause
Action
DEFINITION: The clutch does not engage completely after the pedal is released, after
shifting gears, or the clutch slips during maximum engine loads, such as climbing hills or
high vehicle speeds. Clutch slipping is identified by increase in engine RPM without
increase in vehicle speed.
Review the Symptoms - Clutch and perform the necessary inspections.
Incorrect clutch pedal height, not allowing
the clutch master cylinder to return
Faulty clutch start switch. Refer to Clutch
Pedal Engine Start Switch Replacement.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Clutch - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 1254 1255 1256 1257 ..