Chevrolet Silverado / GMC Sierra. Manual — part 1492

3. Place the contact pad of the J 8001-3 on one of the teeth of the pinion gear closest to

the pinion shaft lock bolt. See Special Tools.

Turn the dial of the J 8001-3 until the needle and the dial face indicate ZERO. See
Special Tools.

4. Tighten the lock nut of the J 8001-3 finger tight. See Special Tools.

5. Pull the pinion gear firmly into the differential case seat.

6. Rotate the pinion gear back and forth.

7. Measure the backlash.

Specification: The backlash for the pinion gears should be 0.076-0.229 mm (0.003-
0.009 in).

10. If the backlash is too large, install a thicker differential side gear shim and check the

backlash.

11. If the backlash is too small, install a thinner differential side gear shim and check the

backlash again.

Differential side gear shims are available in the following sizes:

Shim Sizes:

0.254 mm (0.010 in)

0.381 mm (0.015 in)

0.508 mm (0.020 in)

0.635 mm (0.025 in)

0.762 mm (0.030 in)

0.889 mm (0.035 in)

1.016 mm (0.040 in)

1.143 mm (0.045 in)

Thrust Block Clearance Adjustment

2008 Chevrolet Silverado 1500

2008 Driveline/Axle Rear Drive Axle - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 288: View Of Left Side Gear Thrust Washer
Courtesy of GENERAL MOTORS CORP.

1. Install the locking differential clutch disc thrust washer into the left side or flange-end of the

differential case.

IMPORTANT: The left and right side gear backlash measurements must be

done before the thrust block measurement can be completed.

2008 Chevrolet Silverado 1500

2008 Driveline/Axle Rear Drive Axle - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado