Cleaning; Axle Housing; Differential; Ring And Pinion Gear - GMC T Series 1994 Repair Manual

CLEANING

Do not steam clean drive parts having ground and
polished surfaces such as gears, bearings, and shafts.
All parts should be disassembled before cleaning.
These parts should be cleaned in a suitable solvent.
Parts should be thoroughly dried immediately after
cleaning. Use soft, clean, lintless rags. Parts may be
dried with compressed air. Do not allow the bearings to
spin while drying them with compressed air.
INSPECTION
It is critical to carefully and thoroughly inspect all
drive unit parts before assembly.
Thorough inspection of the drive parts for wear or
stress and subsequent replacement of worn parts will
eliminate costly drive component repair after reassem­
bly.

AXLE HOUSING

Inspect
• Axle housing bore for nicks or burrs that would
prevent the outer diameter of the pinion seal from
sealing. Remove any burrs that are found.
• Bearing cup surfaces for nicks or burrs. Remove
any burrs that are found.
• Housing for cracks. Replace the housing if any
cracks are found.
• 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, spalling.
• Thrust washers for wear.
• The fit of the side gears in the differential case.
• Fit of the side gear on the axle shafts.
• Differential case for cracks and scoring.
• All parts for wear and replace if necessary.

RING AND PINION GEAR

• Ring and pinion gears are matched sets and both
are replaced any time a replacement of either is
necessary.
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 gear on the pinion flange.
CLEANING AND INSPECTION
• The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks which would cause dam­
age to the seal's inside diameter and result in an
oil leak.
• All worn or broken parts and replace if necessary.
9
Important
A new pinion flange must be replaced when the
ring gear and pinion gear are replaced to maintain
proper system balance.

BEARINGS

Inspect
L*
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 replace them in sets.
• Low m ile a g e bearings m ay have very sm all
scratches and pits on the rollers and bearing cups
from the initial preload. Do not replace a bearing
for this reason.
THRUST WASHERS, SHIMS, AND ADJUSTER
SLEEVES
1 3
Inspect
Shims and thrust washers for cracks and chips.
Dam aged shim s should be replaced with an
equal-size service shim.
Adjuster sleeves for damaged threads. Replace if
required.

SHIFT MECHANISM

Inspect (Figure 1)
Carrier connector (9) for damaged splines and
teeth. Replace as required.
Shift fork (17) for wear, scoring, and damage to
thrust surfaces. Replace if needed.
Sleeve (22) and inner output shaft (23) for dam­
aged splines and teeth. Replace if necessary.
Spring (16) for breakage.
Important
Lubricate all seal lips, bearings, gears, and bearing
surfaces with axle lubricant prior to assembly.