Inspection; Assembly Of Axle; Differential Case Assembly - Chevrolet 1991 Light Duty Truck Repair Manual

INSPECTION

It is very important 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
| y | Inspect
• Carrier 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" in this section.
DIFFERENTIAL
Inspect
• Pinion gear shaft for unusual wear.
• Pinion gear and side gear teeth for wear, cracks,
scoring, spading.
• Thrust washers for wear.
• The fit of the differential side gears in the differen­
tial case.
• Fit of the side gear on the axle shafts.
• Differential case for cracks and scoring.
• Replace all worn parts.
PINION AND RING GEAR
Inspect
Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
Pinion gear splines for wear.
Pinion flange splines for wear.
Fit of the pinion flange on the pinion gear.
Im portant
m
• Lubricate all the seal lips, bearings, gears, and
bearing surfaces with axle lubricant prior to
assembly.

DIFFERENTIAL CASE ASSEMBLY

s
Install or Connect (Figures 1, 2 and 15)
Tool Required:
J 33790 Side Bearing Installer
1. Thrust washers (53) and side gears (54) into the
differential case (35).
• If the same gears and washers are being used,
install them on the same side from which they
were removed.
ALL W HEEL DRIVE FRONT AXLE 4C5-3
BEARINGS
E
THRUST WASHERS, SHIMS AND ADJUSTER
SLEEVES
i *

ASSEMBLY OF AXLE

• 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.
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 front 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.
Inspect
• Shims and thrust washers for cracks and chips.
Damaged shims should be replaced with an equal­
ly sized service shim.
• Adjuster sleeves for damaged threads. Replace if
required.
2. Pinion gears (56).
• Position one pinion gear (56) between the side
gears and rotate the gears until the pinion gear
is directly opposite the opening in the case.
• Place the other pinion gear (56) between the
side gears, making sure the hole in both pinion
gears line up.
3. Thrust washers (55).
• Rotate the pinion gears toward the opening just
enough to permit the sliding in of the thrust wash­
ers.
4. Shaft (52) and bolt (36).
5. Ring gear (37) onto the differential case (35).
NOTICE: See Notice on page 4C5-1 of this
section.