Differential; Pinion And Ring Gear; Bearings; Shims - GMC T Series 1994 Repair Manual

• The housing for cracks. Replace the housing if any
cracks are found.
• The housing for foreign material such as metal
chips, dirt, or rust. Refer to " Cleaning."

DIFFERENTIAL

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 side gears in the differential case.
• The fit of the side gears on the axle shafts.
• Differential case for cracks and scoring.
• All parts for wear and replace if necessary.

PINION AND RING GEAR

Ring and pinion gears are matched sets and both are
replaced any time a replacement of either is necessary.
Inspect
l ?
• Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
• Pinion gear splines for wear.
• Pinion flange splines for wear.
• The fit of the pinion gear splines on the pinion
flange.
• The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks that could cause dam­
age to the seal's inside diameter and result in an
oil leak.
• All worn or broken parts and replace if necessary.
Important
A new pinion flange must also be replaced when
ring gear and pinion gear are replaced to maintain
proper system balance.

BEARINGS

Inspect
Bearings for smooth rotation after oiling them.
Bearing rollers for wear.
Bearing cups for wear, cracks, brinelling, and scor­
ing.
Important
When replacing worn or cracked bearings and
cups, make sure to to replace them in sets.
Ring gear and pinion gear for wear and replace
them as a set if worn.
Important
• Low m ileage bearings m ay have very sm all
scratches and pits on the rollers and the bearing
cups from the initial preload. Do not replace a
bearing for this reason.

SHIMS

Inspect
I ?
• Shims for cracks and chips. Damaged shims
should be replaced with an equal size service
shim.

ASSEMBLY OF THE REAR AXLE

-►+ Install or Connect (Figures 2 and 12 through
28)
Tools Required:
J 29710 Differential Side Bearing Installer
J 7818 Rear Pinion Bearing Cup Installer
J 8092 Driver Handle
•Pinion bearing cups using J 29710, J 7818, and
J 8092.

PINION DEPTH ADJUSTMENT

Tools Required:
J 21777-40 Rear Pilot Washer
J 21777-42 Front Pilot Washer
J 21777-43 Stud Assembly— Bolt
J 21777-45 Side Bearing Discs
J 23597-1 Arbor
J 23597-11 Gage Plate
J 8001 Dial Indicator
1. Clean all the gage parts.
2. Lubricate the front and rear pinion bearings with
axle lubricant (figures 14 and 15).
3. Place the bearings into the pinion bearing cups.