Chevrolet 1991 Light Duty Truck Repair Manual page 507

• Perform the cutting operation with a ridge
reamer (figure 16).
• Turn the crankshaft until the piston is at TDC.
• Remove the cloth and cuttings.
2. Connecting rod cap. Check the connecting rod
and cap for identification marks. Mark the parts if
required. The connecting rod and cap must be
kept together as mating parts.
3. Connecting rod and piston.
• Attach two short pieces of 10 mm (3/8-inch)
hose to the connecting rod bolts (figure 17).
This will protect the crankshaft journal during
removal.
• Push the connecting rod and piston out of the
bore.
• After removal, assemble the connecting rod
and cap.
FLYWHEEL REMOVAL
|» + | Remove or Disconnect (Figure 18)
1. Bolts (141).
2 Flywheel (140).
CRANKSHAFT REMOVAL
l» + | Remove or Disconnect (Figure 18)
• Check the main bearing caps for location mark­
ings. Mark the caps if necessary. The caps must
be returned to their original locations during the
engine assembly.
1. Bolts (146).
2 Main bearing caps (147).
3. Crankshaft (148). Lift the crankshaft straight up,
taking care to avoid damage to the crankshaft jour­
nals and thrust flange surfaces.
4. Rear crankshaft seal halves (142 and 145).
5. Main bearing inserts (143 and 144).
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 method
and tools, is most important. The rebuilt engine cannot
be expected to perform properly if parts worn beyond
acceptable limits are reused.
BLOCK
P g j Clean
1. Block in solvent.
2. Block gasket surfaces.
3. Cylinder bores.
4. Oil galleries and passages.
5. Scale deposits from the coolant passages.
6.2L D IESEL ENGINE 6A7-11
142. Upper Seal Half
143. Upper Main Bearing Insert
144. Lower Main Bearing Insert
________________________________________ B8070
Figure 18—Crankshaft and Components
| y | 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 ID at all bearing supports.
— The area where the main bearing inserts con­
tact the main bearing bore must be free of
burrs and scratches.
5. Head gasket surface for scratches, burrs and dam­
age.
148. Crankshaft