Chevrolet Silverado / GMC Sierra. Service manual — part 1496

2. Loosely clamp the J 8001-3 (2) onto the stem on the J 7872 (1). See Special Tools.

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 between the differential pinion gear and the locking
differential side gear should be 0.051-0.203 mm (0.002-0.008 in).

11. If the backlash is too large, install a thicker locking differential clutch disc thrust washer

and recheck the backlash.

12. If the backlash is too small, install a thinner locking differential clutch disc thrust washer

and recheck the backlash.

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)

0.899 mm (0.035 in)

1.016 mm (0.040 in)

1.143 mm (0.045 in)

1.270 mm (0.050 in)

1.397 mm (0.055 in)

1.524 mm (0.060 in)

Thrust Block Clearance Adjustment

2008 Chevrolet Silverado 1500

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

Fig. 297: View Of Left Side Gear Thrust Washer
Courtesy of GENERAL MOTORS CORP.

1. Install the locking differential side gear thrust washer into 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

Fig. 298: View Of Left Side Gear Cam Unit & Clutch Disc Assembly
Courtesy of GENERAL MOTORS CORP.

2. Install the left side locking differential side gear cam unit and clutch disc assembly into the

differential case.

3. Install the right side differential side gear shim into the differential case.

4. Install the right side locking differential side gear and clutch disc assembly into the

differential case.

5. Install the pinion shaft.

6. Install the pinion shaft bolt.

Tighten: Tighten the pinion shaft bolt finger tight.

2008 Chevrolet Silverado 1500

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

Fig. 299: Installing Brass Drift Between Locking Differential Side Gear & Pinion
Shaft
Courtesy of GENERAL MOTORS CORP.

7. Install a brass drift between the left side gear and the pinion shaft.

Press the brass drift in far enough in order to compress the clutch disc assembly and hold the
left side gear assembly in place.

8. Install a brass drift between the right side gear and the pinion shaft.

Press the brass drift in far enough in order to hold the right side gear assembly in place.

2008 Chevrolet Silverado 1500

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