GMC 4000 Series Service Manual page 159

Sec. 4C
Page 152
REAR HUBS AND BEARINGS
REPAIR
Bearing Cup Replacement
1. Bearing cups are removed by using a mild
steel rod through opposite end of hub and driving
against inner edge of bearing cup. Alternately
drive on opposite sides of cup to avoid cocking cup
and damaging inside of hub.
2. To install new cups, position cup in hub
and drive into place, using a suitable driver or by
using a mild steel rod against outer edge of cup.
If drift is used, alternately drive against opposite
sides to assure driving cup in squarely. Cups must
seat firmly against shoulder in hub.
Inner Oil Seal Sleeve Replacement
1. To remove oil seal sleeve (when used) tap
sleeve around entire circumference with hammer
to stretch the metal; then use a blunt chisel to cut
into the sleeve inner flange. This will loosen the
sleeve sufficiently to permit removal.
IMPORTANT: Do not damage axle housing tube
when chiseling on sleeve.
2. Slide new sleeve over axle housing tube;
then using axle oil seal sleeve driver set J-3822-02,
drive sleeve into place. Use care not to damage
surface on sleeve which will be contacted by the
inner oil seal.
Brake Drum Replacement
1. Demountable Type. The demountable type
drum may be separated from the hub and removed
from the vehicle without disturbing the axle shaft
and hub. The drum is held to the hub by counter­
sunk, slotted screw s, which are easily removed
with a screwdriver.
2. Non-Demountable Type. Construction of the
non-demountable type hub and drum assembly is
such that replacement cannot be accomplished with
the hub assembly installed on the vehicle.
a. Separate the drums and hub by removing
the drum-to-hub retaining bolts, hub stud nuts, or
by pressing out the wheel studs, as applicable.
b. Position brake drum to hub assembly, mak­
ing certain that all drain holes are in alignment.
c. Apply a light, even coating of sealing com­
pound to the hub oil deflector contact surface, and
position deflector to drum.
d. Install drum-to-hub retaining bolts, hub
stud nuts, or p ress wheel studs into drum, as ap­
plicable.
Wheel Bolt Replacement
Wheel bolts are serrated and may also be
swaged in place; however, replacement procedure
remains the same for both types of installation.
Press bolts out of hub flange, using suitable press,
G M C S E R V I C E M A N U A L
then p ress new bolts into place, making sure bolts
are a tight fit. If all bolts were removed, be sure
that hub oil deflector is in position under bolt heads.
single stud failure, caused by a loose running
wheel, all wheel studs should be replaced.
stud to break, but several more studs may become
fatigued to the point of failure, but not actually
breaking. Replacing only the one broken stud and
remounting wheel will then set the stage for a
second and possibly more serious failure. If holes
in wheel have become elongated or enlarged, re­
place wheel.
Hub Stud Replacement
using a conventional stud remover and replacer.
Make sure that studs are firmly bottomed in holes
and that threads are not damaged during installation.
pair operations, lubricate bearings, axle housing
tube, and inside of hub as directed in LUBRICA­
TION (SEC. 0) of this manual. Coat lip of oil seal
and surface contacted by seal lip with wheel bear­
ing grease or equivalent.
TYPE D AND E (Fig. 2)
hub or wheel (hub) and drum assembly. Coat oil
seal case with a thin layer of non-hardening sea l­
ing compound; then press seal in hub until seal lip
seats against hub. Seal lip must point inward and
driving tool used must exert force on outer edge
of oil seal.
axle housing. Place wheel (hub) and drum assem ­
bly or hub on axle housing tube using care not to
'damage the inner oil seal.
bly on axle housing tube and p ress firmly into
place. Install bearing adjusting nut, nut lock, and
lock nut on axle housing tube.
wheel assem blies. Adjust wheel bearings as pre­
viously described under "Bearing Adjustment."
AXLES" (SEC. 4A). Adjust brakes as directed in
BRAKES (SEC. 5) of this manual.
TYPES A, B AND C (Fig. 2)
spacer in hub, install outer bearing cone and roller
IMPORTANT: If any wheel experiences a
A loose running wheel may cause only one
Hub studs can be removed and replaced by
REAR HUB AND BEARING
INSTALLATION
(Refer to Figure 2)
After completing cleaning, inspection, and re­
1. Position inner bearing cone and roller in
2. Make sure oil seal sleeve is in place on
3. Place outer bearing cone and roller assem ­
4. Install tire and rim assem blies or tire and
5. Install axle shafts as directed in "REAR
1. From inner end of hub place axle shaft