GMC S Series 1994, Repair Manual

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133 134
130. Crankshaft
131. Rear Seal
132. Rear Main Bearing Cap
133. Main Bearing Cap
134. Bolt
135. Lower Main Bearing Insert
136. Upper Main Bearing Insert
F9332
Figure 39— Crankshaft and Components (7.4L
Engines)
CLEANING, INSPECTION, AND REPAIR
A solvent tank large enough to hold the larger engine
parts will be needed along with various bristle brushes
and a gasket scraper. A source of compressed air will
be helpful in the cleaning operations.
Precision measuring tools will be required for the
inspection procedure. These include: micrometers, cyl­
inder bore gage, feeler gages, dial indicator set, etc.
The inspection work, performed with the proper meth­
ods and tools, is most important. The rebuilt engine
cannot be expected to perform properly if parts worn
beyond acceptable limits are reused.
BLOCK
Clean (Figures 40, 41, and 42)
1. Block in solvent.
2. Block gasket surfaces.
3. Cylinder bores.
4. Oil galleries and passages (figures 40 and 42).
5. Scale deposits from the coolant passages.
Inspect
1
. All expansion plugs for poor fit or leakage.
2. Hydraulic lifter bores for deep scratches and var­
nish deposits.
3. Block for cracks.
• Cylinder walls.
• Coolant jackets.
• Main bearing webs.
• Engine mount bosses.
4. Main bearing bores and main bearing caps.
• All main bearing bores should be round and
uniform in inside diameter (ID) at all bearing
supports.
i a