GMC PD-4103 Maintenance Manual page 18

GM COACH MAINTENANCE MANUAL
Sec. 2
Page 19
REAR AXLE REPAIR
The following instructions provide procedures
for complete disassembly, cleaning, inspection, re-
pair, and reassembly of rear axle. Axle housing
may be checked for bent condition before axle as-
sembly is removed from coach. The following re-
pair procedure is based on the operations neces-
sary when axle is removed from coach.
AXLE HOUSING CHECK
At regular inspection intervals, or if conditions
indicate that rear axle housing might be bent, hous-
ing should be checked, usin_g the following method.
This check can be made before or after axle is
removed from coach to determine if axle housing
is sprung. Conventional camber and toe-in gauges
can be used to perform inspection.
1. Support axle in level position using blocks
at each spring seat; then check rear wheel bear-
ing adjustment referring to HUBS, WHEELS, AND
BEARINGS (SEC. 19) for bearing information.
2. Check run-out at each rear wheel and re-
place wheels having run-out in excess of 3/32 inch.
3. Check for toe-in and camber at rear wheels.
Rear wheels should not toe in or out more than
1/8 inch, and camber should be zero, plus or minus
1/4 degree. If measurements are not within the
above dimensions, bent or sprung axle housing is
indicated. Make notation of the existing conditions
for use when making corrections later.
4. In cases where bent axle housings are in-
dicated, further checks to determine exact location
of bend should be made after rear axle has been
disassembled; and necessary steps taken to cor-
rect the condition. Any straightening should be
done with axle housing COLD, UNDER NO CIR-
CUMSTANCES SHOULD HEAT BE APPLIED.
AXLE DISASSEMBLY
(Key Numbers in Text Refer to Fig. 3)
Before and during disassembly operations, per-
form following inspections and check all adjust-
ments to determine repairs required.
1. Visually inspect exterior of housing for
leaks and damage; then clean outside of housing
using suitable cleaning equipment.
2. After differential assembly is removed
from housing, check pinion bearings for end
play. Check differential case assembly run-out
and backlash before removal of differential and
make note of same for later reference during re-
pair.
DIFFERENTIAL CARRIER REMOVAL (Fig. 3)
1. Remove axle shafts as previously instructed
under "Axle Shaft Replacement" in this section.
2. Remove drain plug and drain lubricant from
REAR AXLE
housing, then loosen differential carrier stud
nuts.
3. Remove stud nuts (34) and lock washers
(35) from differential carrier studs (33).
4. Be certain that differential carrier is sup-
ported solidly, then proceed to pull complete car-
rier assembly out of housing.
DIFFERENTIAL REMOVAL FROM CARRIER
(Fig. 3)
1. Remove lock wire from bolts (6) which lock
adjusting rings (38).
2. Remove nuts from differential side bearing
cap studs. Make certain that bearing caps (41)
and carrier are marked before removal; then re-
move side bearing caps (41) and cups (40). Lift
out differential assembly including drive gear (1)
and side bearings (39). Remove side bearing ad-
justing rings (38).
DIFFERENTIAL CASE DISASSEMBLY (Fig. 3)
1. Mark both halves of case (11) so halves
may be reassembled in original positions (fig. 2).
2. Remove side bearings (39) from each half
of case, using special bearing puller CS-1047 as
shown in figure 4.
3. Remove lock wire and nuts (4) from bolts
(43) which hold the two halves of differential case
(11) together; then separate halves of case (11).
4. Remove side gears (9), thrust washers (10)
and (3), spider (2), and pinions (42) from differ-
ential case (11).
5. If either drive gear (1) or drive pinion (29)
TP 0750
Figure 2-Differenfial Case Alignment Marks