GMC 1986 P-Truck Service Manual page 391

4B-6 REAR AXLE
ABRASIVE ROLLER WEAR
Pattern on races and rollers caused by fine
abrasives.
Clean all parts and housings, check seals and
bearings and replace if leaking, rough or
noisy.
GALLING
Metal smears on roller ends due to overheat,
lubricant failure or overload.
Replace bearing, check seals and check for
proper lubrication.
Figure 2—Diagnosis Of Tapered Roller Bearings
ABRASJVE STEP WEAR
Pattern on roller ends caused by fine abra­
sives.
Clean all parts and housings, check seals and
bearings and replace if leaking, rough or
noisy.
ETCHING
Bearing surfaces appear gray or grayish black
in color with related etching away of material
usually at roller spacing.
Replace bearings, check seals and check for
proper lubrication.
B-09194