Pontiac firebird 1968 - Assembly-Recondition; Remove and Replace

6-64
1968 PONTIAC SERVICE MANUAL
RIDGE CAUSED BY CYLINDER WEAR
Fig. 6-112 Cylinder Ring Ridge
crankpin or bearing. If the bearing clearance Is
between .0005" and .0025", the clearance is satis-
factory. If clearance is more than .0025", replace
bearing with the next size undersize bearing and
recheck clearance. Bearings are available in .001"
and .002" undersize.
4. Rotate the crankshaft after bearing adjustment
to be sure bearings are not tight.
CONNECTING ROD AND PISTON ASSEMBLY-
REMOVE AND REPLACE
REMOVE
1. Remove oil pan, oil baffle and oil pump (see
Oil Pan - Remove - and Replace).
2. Remove intake manifold and cylinder head on
bank from which piston is to be removed.
3. Rotate crankshaft so crankpin carrying assem-
bly to be replaced projects straight downward (Fig.
6-111).
4. Remove ring ridge (Fig. 6-112) using suitable
ring ridge remover.
5. Remove bearing cap and install connecting rod
bolt guide set J 5239.
6. Carefully remove connecting rod and piston
assembly by pushing out with knurled handle of long
guide (Fig. 6-113).
REPLACE
1. Install connecting rod bolt guide set on con-
necting rod bolts with long handle guide on same
side as oil groove in rod.
2. Using J 6647 or J 5684 (Fig. 6-114) ring com-
pressor, insert piston and connecting rod assembly
Into cylinder so that notch in top of piston is toward
front of engine. Be certain oil spurt hole (Fig. 6-121)
in connecting rod is toward camshaft.
J-5239
Fig. 6-113 Connecting Rod Bolt Guide Set Installed
3. From beneath engine, pull connecting rod, with
bearing shell in place, into position against crankpin.
4. Remove guide set J 5239. - Install bearing cap
and cap nuts and tighten to 43 lb. ft. torque.
5. Replace oil pump and oil baffle, if they were
removed.
6. Install cylinder head and intake manifold.
CONNECTING ROD AND PISTON ASSEMBLY-
RECONDITION
NOTE; Use care at all times when handling and
servicing connecting rods and pistons. To prevent
- possible damage to these units, do not clamp rod
or piston in vise since they may become distorted.
350 J 6647
400 & 428 J 5684 .
Fig. 6-114 Instal ling Piston Assembly