GMC 1989 Light Duty Truck Repair Manual page 237

• There are three adjustments to be made:
(1) Left side gear backlash.
(2) Right side gear backlash.
(3) Thrust block clearance.
Right Side Gear Blacklash Adjustment
1 . Install the cam unit and thrust washer (36) to the
right case half.
2. Clamp the cam unit in place using a set of washers,
nut, and a bolt long enough to hold the cam unit in
place (figure 13).
3. Place the pinion gears and thrust washers on the
pinion yoke.
4. Install the yoke firmly to the differential case half
(figure 14).
5. Loosen the nut, and index one pinion gear tooth to
point downward (perpindicular to the case half face).
Tighten the nut.
6
. Mount a dial indicator on the case half face using a
magnetic base (figure 15).
7. Place the stem of the dial indicator on the pinion
gear tooth.
LOCKING DIFFERENTIALS 4B7-7