Backlash Adjustment

Backlash Adjustment
Adjust the backlash by means of moving the side bearing adjuster sleeves which move the case and ring gear assembly closer to or farther from the pinion.
Also use the adjuster sleeves in order to set the side bearing preload.
^ If the left side adjuster sleeve is moved in, along with an equal outward movement of the right side adjuster, the backlash will increase.
^ If the left side adjuster sleeve is moved out, along with an equal inward movement of the right side adjuster, the backlash will decrease.

Testing Procedure





1. Wipe clean the differential case, the ring gear and the differential carrier housing of lubricant. Carefully clean each tooth of the ring gear.
2. Use a medium stiff brush in order to sparingly apply gear marking compound GM P/N 1052351 (Canadian P/N 10953497) or equivalent to all of the ring gear teeth.

Important: Avoid turning the ring gear excessively.

3. Using a wrench, turn the drive pinion flange/yoke so that the ring gear rotates at least 3 full revolutions.
4. Turn the drive pinion flange/yoke in the opposite direction so that the ring gear rotates at least 3 full revolutions in the opposite direction.
5. Observe the pattern on the ring gear teeth. Compare the pattern with the following illustrations.

Correct Contact Pattern

Condition





The backlash and pinion depth is correct.

Correction
None required.

Service Hints
Loose bearing on the drive pinion or in the differential case may cause patterns that vary. If the contact pattern varies, inspect the following preload settings:
^ Total assembly
^ Differential case
^ Drive pinion If these settings are correct, inspect for damage or incorrectly assembled parts.

Drive Side Heel - Coast Side Toe Contact Pattern

Condition





The pinion depth is incorrect. The drive pinion is too far away from the ring gear.

Correction
Adjust the pinion depth of drive pinion.

Drive Side Toe - Coast Side Heel Contact Pattern

Condition





The pinion depth is incorrect. The drive pinion is too close to the ring gear.

Correction
Adjust the pinion depth of drive pinion.

Drive Side Heel - Coast Side Heel Contact Pattern

Condition





The backlash is incorrect. The ring gear is too far away from the drive pinion.

Correction
Decrease the backlash. Move the ring gear closer to the drive pinion by adjusting the side bearing adjuster sleeves.

Drive Side Toe - Coast Side Toe Contact Pattern

Condition





The backlash is incorrect. The ring gear is too close to the drive pinion.

Correction
Increase the backlash. Move the ring gear away from the drive pinion by adjusting the side bearing adjuster sleeves.