Assembly Of The Rear Axle - Chevrolet 1991 Light Duty Truck Repair Manual

• The housing for foreign material such as metal
chips, dirt, or rust. Refer to "Cleaning" in this
section.
DIFFERENTIAL
W Inspect
• Pinion gear shaft for unusual wear.
• Pinion gear and side gear teeth for wear, cracks,
scoring, and spalling.
• Thrust washers for wear.
• The fit of the differential side gears in the differen­
tial case.
• The fit of the side gears on the axle shafts.
• Differential case for cracks and scoring.
• Replace all worn parts.
PINION AND RING GEAR
| P | Inspect
• Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
• Pinion splines for wear.
• Pinion flange splines for wear.
• The fit of the pinion flange on the pinion gear.
• The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks which would cause
damage to the seal's inside diameter and result in
an oil leak.
• Replace all worn or broken parts.
• Ring and pinion gears are matched sets and are
both replaced any time a replacement of either is
necessary.
BEARINGS
| j y | Inspect
• Bearings visually and by feel.
• The bearings should feel smooth when oiled and
rotated while applying as much hand pressure as
possible.
• The large end of the bearing rollers for wear. This
is where tapered roller bearing wear is most evi­
dent.
• Bearing cups for wear, cracks, brinelling and scor­
ing.
• Bearings and cups are only replaced as sets.
• If the rear axle was operated for an extended
period of time with very loose bearings, the ring
gear and drive pinion will also require replace­
ment.
• Low mileage bearings may have very small
scratches and pits on the rollers and the bearing
cups from the initial preload. Do not replace a
bearing for this reason.
• Bearing caps for cracks or chips.
SHIMS
[ y l Inspect
• Shims for cracks and chips. Damaged shims
should be replaced with an equally sized service
shim.
9 1/2-INCH RING GEAR 4B3-5

ASSEMBLY OF THE REAR AXLE

|-»4^ in stall or Connect (Figures 10 and 11)
Tools Required:
J 7817 Front Pinion Bearing Cup Installer
J 22306 Rear Pinion Bearing Cup Installer
J 8092 Driver Handle
1. Front pinion bearing cup (10) using J 7817 and
J 8092.
2. Rear pinion bearing cup (13) using J 22306 and
J 8092.
PINION DEPTH ADJUSTMENT
Tools Required:
J 8001 Dial Indicator Gage Set
J 21777-1 Arbor
J 21777-8 Rear Pilot Washer
J 21777-42 Front Pilot Washer
J 21777-43 Stud Assembly—Bolt
J 21777-85 Gage Plate
J 21777-86 Side Bearing Disc
Figure 11—Installing the Rear Pinion Bearing Cup