Backlash Inspection and Adjustment

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

J 8001 Dial Indicator Set
J 36599-A Side Bearing Nut Wrench. See Special Tools .
J 36615 Side Bearing Nut Wrench. See Special Tools .

Remove all alignment marks made previously and re-mark the location of the differential adjuster nut sleeves in relation to the differential carrier assembly case halves.
Ensure that the notches can be counted when turned.

Fig 1: Installing J 8001-1, J 8001-2 & J 8001-3 To Pinion Yoke

Courtesy of GENERAL MOTORS CORP.

Install the J 8001-1 (1, 2), the J 8001-2 (3), and the J 8001-3 (4) as shown.
Ensure that the button contacts the outer edge of the pinion yoke and that the plunger is at a right angle to the pinion yoke.
Move the pinion yoke back and forth through the pinion yoke's free play while not allowing the ring gear to move.
Record the dial indicator reading.
To determine the actual backlash, divide the dial indicator reading by 2.
An actual dial indicator reading of 0.16 mm (0.006 in) means that there is actually 0.08 mm (0.003 in) backlash.

Specification: The backlash between the ring gear and the drive pinion should be between 0.08-0.25 mm (0.003-0.010 in) with a preferred specification of 0.13-0.18 mm (0.005-0.007 in).

IMPORTANT: When adjusting the backlash, observe the following:

Always turn the left and the right differential adjuster nut sleeves in equal amounts.
Turning the differential adjuster nut sleeves one notch will change the backlash about 0.08 mm (0.003 in).

If the backlash is too small, increase the backlash by turning the right differential adjuster nut out using the J 36599-A , 8. See Special Tools .25 inch axle, or the J 36615 , 9. See Special Tools .25 inch axle, and the left differential adjuster nut using the J 36599-A until the correct backlash is obtained. See Special Tools . For the late 8.25 "LOCK RING" design front axle, turn out the right differential adjuster nut in small increments using the J 36599-A and the left differential adjuster nut in small increments until the correct backlash is obtained. See Special Tools .
If the backlash is too large, decrease the backlash by turning the left differential adjuster nut out using the J 36599-A and the right differential adjuster nut in using the J 36599-A , 8. See Special Tools .25 inch axle, or the J 36615 , 9. See Special Tools .25 inch axle, until the correct backlash is obtained. For the late 8.25 "LOCK RING" design front axle, turn out the left differential adjuster nut out in small increments using the J 36599-A and the right differential adjuster nut in small increments until the correct backlash is obtained. See Special Tools .
Recheck the rotating torque of the pinion and differential assembly and adjust, if necessary. Refer to Differential Carrier Assembly Assemble (9.25 Inch Axle) or Differential Carrier Assembly Assemble (8.25 Inch Axle Lock Ring Style) .
Once the backlash and bearing preload is within specifications, remove the alignment markings and place new alignment marks between the differential bearing adjuster nut and the differential carrier assembly case.
Continue the assembly of the differential carrier. Refer to Differential Carrier Assembly Assemble (9.25 Inch Axle) or Differential Carrier Assembly Assemble (8.25 Inch Axle Lock Ring Style) .