GMC S Series 1994, Repair Manual

Page: 125 / 919

5. Install the differential bearing caps and bolts.
Tighten
S i
• Bolts to 75 N.m (55 lbs. ft.).
6. Check and record the backlash at three or four
points around the ring gear.
• The pinion must be held stationary when check­
ing backlash.
• The backlash should be the same at each point
within 0.05 mm (0.002 inch). If the backlash
varies more than 0.05 mm (0.002 inch), check
for burrs, a distorted case flange, or uneven
bolting conditions.
7. Backlash at the minimum lash point measured
should be 0.13 to 0.23 mm (0.005 to 0.009 inch)
for all new gear sets.
8. If the backlash is not within specifications, move
the ring gear in or out from the pinion by increasing
the thickness of one shim, and decreasing the
thickness of the other shim the same amount. This
will maintain the correct axle side bearing preload.
• Moving 0.05 mm (0.002 inch) worth of shim
from one side of the differential to the other will
change the backlash adjustment by 0.03 mm
(0.001 inch).
9. When the backlash is correctly adjusted, remove
the bearing caps and shim packs.
10. Select a shim 0.10-mm (0.004-inch) thicker than
the one removed from the left side. Insert this shim
between the spacer and left bearing race (figure
25).
11. Install the left bearing cap and bolts.
• Do not tighten.
12. Select a shim 0.10-mm (0.004-inch) thicker than
the one removed from the right side. Insert the
shim between the spacer and right bearing race,
and drive the shim into place (figure 25).
13. Install the right side bearing cap, and bolts.
$
Tighten
• Bolts to 75 N.m (55 lbs. ft.).
14. Recheck the backlash and correct as necessary.
GEAR TO O TH
PATTERN CHECK
Checking the ring gear to pinion tooth pattern is done
only after setting up the axle according to the methods
in this section. The pattern check is NEVER used as an
initial check or instead of checking pinion depth and
backlash adjustments. This check is only used to verify
the correct adjustment of the gear set after setup.
1. Wipe all oil out of the housing and carefully clean
each tooth of the ring gear (figure 29).
2. Apply gear marking compound (GM P/N 1052351
or equivalent) to all ring gear teeth using a medi-
um-stiff brush. When properly used, the area of
pinion tooth contact will be visible when a hand
load is applied.
2. Axle Shaft
3. “ C ” Lock
30. Pinion Shaft
Lock Bolt
F9400
Figure 28— "C" Lock and Axle Shaft Seated in the
Side Gear