Pontiac tempest 1968 - Crankshaft-Remove and Replace

6-32
1968 PONTIAC SERVICE MANUAL
Incorrect ring gap indicates that wrong size rings
are being used. If rings are selected according to
the size of the bore (standard
o
005
TT
, oversize, etc)
they should have proper gap. It should not be neces-
sary to alter ring gap by filing.
4. Install rings on piston using J 8021 to prevent
breakage or fracture of rings, or damage to pistons.
5. Measure side clearance of rings in ring groove
(Fig. 6-63) as each ring is installed. Clearance with
new pistons and rings should be ,0015-,0050.
If side clearance is excessive, piston should be
replaced.
CONNECTING ROD AND PISTON ASSEMBLY--
REPLACE
1. Install connecting rod bolt guide set J 5239 on
connecting rod bolts (Fig. 6-64).
2. Using piston ring compressor J 6647, insert
rod and piston assembly into cylinder so notch in
top of piston is facing front of engine (Fig. 6-65).
3. From beneath engine, pull connecting rod with
bearing into place against crankpin.
4. Remove guide set J 5239 and install bearing
cap. Tighten cap nuts to 33 lb. ft.
5. Install oil pan.
6. Install cylinder head, intake and exhaust mani-
fold as an assembly.
7. Connect fuel line and vacuum lines to
carburetor.
8. Install rocker arm cover.
CRANKSHAFT-REMOVE AND REPLACE
REMOVE
1. Remove engine from vehicle.
2. Remove clutch from engine.
3. Mount engine on suitable stand.
Fig. 6-64 Connecting Rod Guide Tool
Fig. 6-65 Installing Piston in Cylinder
4. Remove spark plugs.
5. Remove fan and fan pulley.
6. Remove harmonic balancer.
7. Remove oil pan and crankcase front cover.
8. Remove connecting rod bearing caps with bear-
ings and identify each for reinstallation.
9. Push connecting rod and piston assemblies away
from crankshaft.
10. Remove main bearing caps with bearings and
identify for reinstallation.
11. Remove crankshaft.
REPLACE
1. With upper bearings installed position crank-
shaft in block.
2. Using new seals in rear main bearing cap
install main bearing caps (with lower bearings), but
do not tighten cap bolts.
3. Pull connecting rods (with upper bearings in-
stalled) and pistons into place.
4. Install rod bearing caps (with bearings), but do
not tighten nuts.
5. With rubber mallet hit both ends of crankshaft
to center thrust bearing.
6. Tighten main bearing caps 100 lb. ft.
7. Tighten connecting rod bearing caps 33 lb. ft.
8. Install key from old crankshaft keyway in new
crankshaft.