GMC 1982 Light Duty Truck Service Manual page 440

4 B 1 -1 2 REAR A X L E
Fig. 4B1-32--lnstalling Pinion Rear Bearing Cup
for nicks. Remove as necessary. Clean the bores and the
installation tools.
5. Lubricate both bearing cups with liberal amounts of
hypoid lubricant.
6. Install the rear cup, with the large end against the bore
shoulder, using Installer J-8608 for 8-1/2" ring gear
and J-0270-14 for the 8 -7 /8 " ring gear or J-22306 for
the 9 1/2" ring gear as shown in figure 4BI-32.
7. Install the front cup, with the large end against the bore
shoulder, using Installer J - 8 6 1 1-01 for the 8 -1 /2 " ring
gear or J-7137 for the 8 -7 /8 " ring gear or J-7818 for
the 9 1/2" ring gear as shown in figure 4B1-33.
8. Check both bores to make sure cups are fully seated.
S etting Pinion D epth a n d In s ta llin g Pinion Bearings
If the original ring gear and pinion and the pinion rear
bearing assembly are to be reinstalled, the original shim
thickness may be used.
Ring and pinion gear sets are matched in a special test
Fig. 4B1 -33— Installing Pinion Front Bearing Cup
machine which permits adjustment of pinion depth in ring
gear until a point is reached where best operation and proper
tooth contact under load is obtained. At this point, the
setting of the pinion with reference to the centerline of the
ring gear is indicated by the machine. This setting may vary
slightly from the design or " nom inal"
allowable variation in machining the parts. W hen a pinion is
found haivng a plus or minus reading recorded in
thousandths on the rear face of the pinion, this indicates that
the pinion during testing was found to have best tooth
contact at a position varying from design or nominal depth.
In order to com pensate for all of the allowable
machining variables, a procedure of gaging the carrier and
shimming the pinion has been developed. After gaging a
carrier, the assembler must install the appropriate shim
between the drive pinion shoulder and rear bearing so that
pinion depth can be adjusted to the required position for best
tooth contact in each axle assembly.
Proper pinion depth is determined with Pinion Setting
Gage J-21777-01.
1. Clean the housing assembly and all gage parts to insure
accurate measurements.
2. Lubricate front and rear pinion bearings which will be
used in final assembly and position them in their
respective races in the carrier.
3. Use cloverleaf gage plate J-21777-29 for 8-1/2" ring
gear or J-2 1777-36 for 8-7/8" ring gear or J-21777-85
for 9 1/2" ring gear mounted on preload stud J - 2 1777-
43 insert stud through rear bearing and pilot J - 2 1777-
35, or J - 2 1777-8 for the 9 1/2" ring gear, and through
front bearing and pilot J - 2 1777-42. Install the hex nut
until snug and rotate the bearings to make sure they are
properly seated. See figure 4B1-34 for illustration of
proper positioning.
4. Hold the preload stud stationary with a wrench on the
flats and tighten hex nut. Tighten until 2.2 N-m (20 in.
lbs.) of torque are required to rotate the bearings, as
shown in figure 4B1-35.
5. Mount the side beairng discs J - 2 1777-45 or J - 2 1777-86
on the ends of arbor J - 2 1777-1, using the step of the
disc that corresponds to the bore of the carrier.
Fig. 4Bl-34--Gage Plate Installed
setting due to