Backlash Adjustment (9.75, 10.5 and 10.75 Inch Axles)

Backlash Adjustment (9.75, 10.5 and 10.75 Inch Axles)


Special Tools
* J 8001 Dial Indicator Set
* J 24429 Side Bearing Backlash Spanner
* J 25025 Guide Pins






1. Install the J 25025-1 and the J 8001 to the axle housing as shown.
2. Place the indicator stem of the J 8001-3 at the heel end of a gear tooth.
3. Set the J 8001-3 so that the stem is aligned with the gear rotation and perpendicular to the tooth angle.
4. Preload the dial of the J 8001-3 .
Align the needle and the dial face of the J 8001-3 to ZERO.
5. While holding the drive pinion stationary, move the ring gear back and forth.
Measure and record the backlash.
6. Repeat the measuring procedure at eight points around the ring gear.

The difference between the backlash at all of the measuring points should not vary by more than 0.05 mm (0.002 in).

7. If the difference between the backlash at all of the measuring points varies by more than 0.05 mm (0.002 in), inspect for the following conditions:

* Burrs
* A distorted case flange
* Uneven bolting

8. If the difference between all the measuring points is within specifications, the backlash at the minimum lash point measured should be:

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 backlash of 0.13-0.18 mm (0.005-0.007 in).

9. If the backlash is too small, increase the backlash by turning the left differential bearing adjuster in one slot and the right differential bearing adjuster out one slot using the J 24429 until the correct backlash is obtained.
10. If the backlash is too large, decrease the backlash by turning the right differential bearing adjuster in one slot and the left differential bearing adjuster out one slot using the J 24429 until the correct backlash is obtained.
11. Recheck the backlash following the steps above to verify that the backlash is within specifications.

Notice: Refer to Fastener Notice .

12. Tighten the differential bearing caps and bolts.

Tighten the bolts to 109 N.m (80 lb ft).

13. Recheck the backlash and adjust, if necessary.
14. Once backlash is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection (Gear Tooth Contact Pattern Inspection) .