Prior To Assembly; Crankshaft Rear Oil Seal Installation - GMC 1989 Light Duty Truck Repair Manual

CRANKSHAFT BEARING AVAILABILITY
Main bearings are available in standard and 0.001,
0.002, 0.010, 0.020, and 0.030-inch undersizes. Connecting
rod bearings are available in standard and 0.001, 0.002,
0.010, and 0.020-inch undersizes.
CRANKSHAFT GEAR REPLACEMENT
D isassem ble (Figure 44)
Tool Required:
J-24420-B Puller
Crankshaft gear, using J-24420-B.

PRIOR TO ASSEMBLY

The importance of cleanliness during the assembly
p ro ced ure cannot be overstressed. D irt w ill cause
premature wear of the rebuilt engine.
Lubricate all moving parts lightly with engine oil or
engine assembly lubricant (unless specified otherwise)
during assembly. This will provide initial lubrication when
the engine is started.
CRANKSHAFT REAR OIL
SEAL INSTALLATION
An oil seal installation tool (figure 46) should be
fabricated (if not provided in the seal kit) to prevent seal
dam age during installation. Extreme care should be
ASSEMBLY OF ENGINE
4.8 LITER L6 6A4-23
V A L V E R E M O V A L
Figure 45— Replacing the Oil Filter Bypass Valve
*
A ssem ble (Figure 44)
Tool Required:
J-5590 Gear Installer
• Crankshaft gear, using J-5590.
• Make sure the tim ing mark faces outside.
OIL FILTER RELIEF
VALVE REPLACEMENT
❖
D isassem ble (Figure 45)
• Oil pressure relief valve. Use a screwdriver to pry it
from the block.
*
A ssem ble (Figure 45)
Oil pressure relief valve. Use a % e-inch, thin wall,
deep socket to tap it into place.
- B -
A
i
L n
A. 4 mm
(11/64-inch)
B. 13 mm
(1/ 2 -inch)
C. 0.10 mm (0.004-inch) shim stock
Figure 46— Oil Seal Installation Tool
V A L V E IN S T A L L A T IO N
B-03497
c
\
B-05250