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6A6-6
1977 PONTIAC SERVICE M A N U A L
mallet.
lnstallation
1. Clean gasket surfaces on cylinder head and rocker arm
cover with degreaser then, using a new gasket, place rocker
arm cover on the head, install retaining bolts, and torque to
specifications.
2. On A/C
equipped vehicles, install the A/C
compressor rear brace. Adjust pulley belt to specifications.
3. Install carburetor heat stove pipe.
4. Connect electrical wiring harness at clips on rocker
arm cover.
5. Connect crankcase ventilation hoses.
6. Install air cleaner, start engine and check for leaks.
VALVE MECHANISM
Removal
1. Remove rocker arm covers as previously outlined.
2. Remove rocker arm nuts, rocker arm balls, rocker
arms and push rods.
NOTE: Place rocker arms, rocker arm balls and push
rods in a rack so they may be reinstalled in the same
locations.
lnstallation and Adjustment
NOTE: Whenever new rocker arms and/or rocker arm
balls are being installed, coat bearing surfaces of rocker
arms and rocker arm balls with "Molykote" or its
equivalent.
1. Install push rods. Be sure push rods seat in lifter
sockets.
2. Install rocker arms, rocker arm balls and rocker arm
nuts. Tighten rocker arm nuts until all lash is eliminated.
3. Adjust valves when lifter is on base circle of camshaft
lobe as follows:
a. Crank engine until mark on torsional damper lines up
with center or
"0"
mark on the timing tab fastened to the
crankcase front cover and the engine is in the number 1 firing
position. This may be determined by placing fingers on the
number 1 valve as the mark on the damper comes near the
"0" mark on the crankcase front cover. If the valves are not
moving, the engine is in the number 1 firing position. If the
valves move as the mark comes up to the timing tab, the
engine is in number 6 firing position and should be turned
over one more time to reach the number 1 position.
b. With the engine in the number 1 firing position as
determined above, the following valves may be adjusted.
Exhaust
-
1, 3, 4, 8
Intake
-
1, 2, 5, 7
c. Back out adjusting nut until lash is felt at the push
rod, then turn in adjusting nut until all lash is removed. This
can be determined by checking push rod side play while
turning adjusting nut (Fig. 6A6-5). When play has been
removed, turn adjusting nut in one full additional turn (to
center lifter plunger).
d. Crank the engine one revolution until the pointer "0"
mark and torsional damper mark are again in alignment. This
is number 6 firing position. With the engine in this positon,
the following valves may be adjusted.
Fig. 6A6-5 Valve Adjustment (Typical)
Exhaust
-
2, 5, 6, 7
Intake
-
3, 4, 6, 8
4. Install rocker arm covers as previously outlined.
5. Start engine and adjust carburetor idle speed.
VALVE STEM OIL SEAL AND/OR
VALVE SPRING
Removal
1. Remove rocker arm cover as previously outlined.
2. Remove spark plug, rocker arm and push rod on the
cylinder(s) to be serviced.
3. Install air line adapter Tool J 23590 to spark plug port
and apply compressed air to hold the valves in place.
4. Using Tool J 5892 to compress the valve spring,
remove the valve locks, valve cap and valve spring and
damper (Fig. 6A6-6).
5. Remove the valve stem oil seal.
Installation
NOTE: A light coat of oil on the seal will help prevent
twisting.
2. Install the valve locks and release the compressor tool
making sure the locks seat properly in the upper groove of
the valve stem.
NOTE: Grease may be used to hold the locks in place
while releasing the compressor tool.
3. Install spark plug and torque to specification.
4.
Install and adjust valve mechanism as previously
outlined.
VALVE LIFTERS
Hydraulic valve lifters very seldom require attention.
The lifters are extremely simple in design, readjustments are
not necessary, and servicing of the lifters requires only that
care and cleanliness be exercised in the handling of parts (see
Diagnosis section).
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