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1977 PONTIAC SERVICE M A N U A L
2. Inspect connecting rods and connecting rod caps for
cylinder identification. If necessary mark them.
3. Remove connecting rod cap and install Tool J 5239
(3/8") or J 6305 (1 1/32") on studs. Push connecting rod and
piston assembly out of top of cylinder block (Fig. 6A6-50).
NOTE: It will be necessary to turn the crankshaft
slightly to disconnect some of the connecting rod and
piston assemblies and push them out of the cylinder.
Fig. 6A6-50 Removing Connecting Rod and Piston
Assemblies
Disassembly
1. Remove connecting rod bearings from connecting
rods and caps.
NOTE: If connecting rod bearings are being reused,
place them in a rack so they may be reinstalled in their
original rod and cap.
2. Remove piston rings by expanding and sliding them
off the pistons. Tools J 8020 (3-9/16") and J 8032 (4") are
available for this purpose.
3. Place connecting rod and piston assembly on tool J
24086-20. Using an arbor press and piston pin remover, J
24086-8, press the piston pin out of connecting rod and piston
(Fig. 6A6-5 1).
CONNECTING RODS
Cleaning and Inspection
Wash connecting rods in cleaning solvent and dry with
compressed air.
Check for twisted or bent rods and inspect for nicks or
cracks. Replace connecting rods that are damaged.
PISTONS
Cleaning and lnspection
Clean varnish from piston skirts and pins with a cleaning
solvent. D O NOT WIRE BRUSH ANY PART O F T H E
PISTON. Clean the ring grooves with a groove cleaner and
make sure oil ring holes and slots are clean.
P I S T O N P I N
REMOVER
J- 24086-8
FIXTURE & .
Fig. 6A6-51 Disassembling Connecting Rod and Piston
Assemblies
Inspect the piston for cracked ring lands, skirts or pin
bosses, wavy or worn ring lands, scu'ffed or damaged skirts,
eroded areas at top of the piston. Replace pistons that are
damaged or show signs of excessive wear.
Inspect the grooves for nicks or burrs that might cause
the rings to hang up.
Measure piston skirt (across center line of piston pin)
and check clearance as outlined under "Piston Selection".
PISTON PINS
Cleaning and lnspection
The piston pin clearance is designed to maintain
adequate clearance under all engine operating conditions.
Because of this, the piston and piston pin are a matched set
and not serviced separately.
Inspect piston pin bores and piston pins for wear. Piston
pin bores and piston pins must be free of varnish or scuffing
when being measured. The piston pin should be measured
with a micrometer and the piston pin bore should be
measured with a dial bore gage or an inside micrometer. If
clearance is in excess of the .00lU wear limit, the piston and
piston pin assembly should be replaced.
Assembly
1. Lubricate piston pin holes in piston and connecting
rod to facilitate installation of pin.
2. Place connecting rod in piston and hold in place with
piston pin guide and piston pin. Place assembly on fixture and
support assembly (Fig. 6A6-52).
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