GMC 1982 Light Duty Truck Service Manual page 488

4B6-6 REAR AXLE
the face of the side gear. Force the screwdriver in until
the clutch pack is compressed.
7. Check the backlash between side gear and pinion gears.
If backlash does not fall into the range of .005" to
.008", adjust the shim dimension as required.
Increasing shim thickness will decrease backlash; to
increase backlash, decrease the thickness of the shim.
Service shims are availabel from .070" to .122" in
increments of .004 ".
8. Remove the pinion shaft, pinion gears, side gear, clutch
pack and shim from the case.
9. Install the opposite gear, clutch pack and original shim
into the opposite side of the case. Place both pinion
gears, and thrust washers into position, and install the
pinion shaft.
10. Follow the procedure in steps 5, 6 and 7 to determine
the proper shim dimension.
11. When the proper shims have been determined to
achieve .005" to .008" backlash between both pinion
gears and both side gears, install shims, clutch packs
and side gears into case.
12. Mount the case onto the axle shaft locked in a vise.
Place both pinions and thrust washers into position-
180°-apart-and carefully "roll in" by turning the case
on the shaft.
A large "C" clamp may be used to apply slight
compression against pinion gears to aid the "rolling in"
procedure.
13. Tap the preload spring into place with a hammer.
14. Install the pinion shaft and lock screw.
15. Install the side bearings and ring gear using the
procedure outlined for conventional units.
16. Place the differential unit in the carrier and adjust ring
gear and pinion backlash, and gear tooth pattern.