Chevrolet CHEVY VAN G10 SERIES Service Manual page 242

CLUTCHES & TRANSM ISSIONS 7-4
Fig. 4 —Checking Pressure Plate L ift W /D ial Indicator
DIAPHRAGM CLUTCH ADJUSTMENT
If clutch fails to release:
1. Check pedal for proper travel and linkage for looseness,
adjustm ents, etc.
2. Check clutch retracting springs for proper reten tio n of
pressure plate to diaphragm spring, replace if necessary.
This can be done w ithout removing clutch from vehicle.
3. If Steps 1 and 2 do n o t cure trouble, check pressure plate
lift w ith dial indicator ( f ig .) as follows:
a. With proper linkage adjustm ent (and lash), zero
indicator w ith clutch fully engaged (pedal up).
b. Measure pressure plate lift at 3 strap b o lt positions
w ith full pedal travel.
N O T E : Use 5 /8 " thick board in place of flo o r mat
to give a positive stop.
All three readings should be w ithin .010" and w ithin
to tal lift readings. If m ore than .010" check retract-
CLUTCH ASSEMBLY
Removal
1. Remove transm ission as outlined in "Transmission Sec­
tio n ."
2. Remove clutch throw out bearing from the fork.
3. Remove clutch fork by pressing it away from its ball
m ounting w ith a screwdriver, until the fork snaps loose
from the ball or remove tha ball stud from rear o f clutch
housing.
N O T E : The retainer may be removed from the
fo rk by prying out w ith a small screwdriver.
4. Install Tool J-5824 to support the clutch assembly during
removal.
COMPONENT REPLACEMENT
Fig. 5 —Gauging Shim R equirem ent
ing springs per step 2. If trouble still exists, loosen
clutch-to-flyw heel m ounting b o lt at position o f
lowest reading (leave oth er bolts tight), pry cover,
away from flyw heel, and insert feeler gauge (fig. 5)
to determ ine thickness o f shim required to bring
0 10
reading w ithin .
T otal lift readings should be as follows;
10" .065 to .075
11" .065 to .085
Make sure proper pedal lash adjustm ent is m ade before
checking.
N O T E : Excessively high readings indicate that the
diaphragm spring is being over stressed which may
eventually cause loss of load and result in slippage.
If above measures fail to correct the trouble, check driven
disc w ith clutch pedal depressed (it should spin freely w ith
transm ission in neutral). If it does n o t, trouble may be:
1. Misalignment betw een pilot bushing in crankshaft and
clutch housing.
2. F aulty clutch pilot bushing.
3. F aulty driven disc.
5. Loosen the clutch attaching bolts one turn at a tim e to
prevent distortion o f clutch cover until diaphragm spring
is released.
6
. Remove clutch pilot and remove clutch assembly from
vehicle.
Installation
1. Install the pressure plate in the cover assembly lining up
the notch mark on pressure plate w ith no tch mark on
flange o f cover.
2. Install pressure plate retracting springs and drive strap to
pressure plate bolts and lockwashers and tighten to
lbs. torque. The clutch is now ready to be installed.
3. H and crank the engine until " X" m ark on flywheel is at
the b o tto m .
4. Install clutch disc, pressure plate and cover assembly and
support them w ith Tool J-5824.
".
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C H E V Y V A N S H O P M A N U A L
ft.