Crankshaft And Bearings - GMC T Series 1994 Repair Manual

Figure 62—Thermostat and Components (5.0L and
5.7L Engines)
Tighten
• Bolts (24) or studs (20) to specifications.
— 5.0L and 5.7L engines: 28 N-m (21 lbs. ft.).
— 7.4L engines: 37 N-m (27 lbs. ft.).
TORSIONAL DAMPER
Inspect
i?
• Torsional damper weight for signs of shifting on the
hub. Replace as needed.
• Area of the torsional damper hub shaft which con­
tacts the crankshaft front seal for roughness or
nicks. Replace the damper if this condition exists.

CRANKSHAFT AND BEARINGS

IQ*
Clean
• Crankshaft with solvent.
• Blow all sludge from the oil passages with com­
pressed air.
• Main bearing inserts. Wipe free of oil with a soft
cloth.
• Seal running surfaces with a non-abrasive cleaner.
Inspect
• Crankshaft for cracks. Use the magnaflux method,
if available.
• Crankpins, main bearing journals, and thrust sur­
faces for scoring, nicks, or damage caused by lack
of lubrication.
• Main bearing inserts for scoring or other damage.
In general, the lower inserts (except the #1 bearing)
show greater wear and the most distress from fatigue.
If, upon inspection, the lower insert is suitable for use, it
can be assumed that the upper insert is also satisfacto­
ry. If the lower insert shows evidence of wear or dam­
age, both the upper and lower inserts must be replaced.