4 - Pinion

1. Ensure that pinion depth and bearing preload are properly adjusted.
2. Install differential case assembly and selected side bearing shims as outlined in ``Differential Bearing Preload Adjustment'' procedure.
3. Rotate assembly to ensure that bearings are properly seated.
4. Mount dial indicator on housing with indicator stem against tooth on ring gear. Use small contact button on indicator stem so that contact can be made at heel end of tooth and position dial indicator with stem in line with gear rotation and perpendicular to gear tooth.
5. Hold pinion stationary and rock ring gear back and forth while reading backlash on indicator.
6. Check backlash at 3 evenly spaced positions around ring gear and record readings. If backlash varies by more than .002 inch at any position, check ring gear installation and runout, and correct as needed.
7. If backlash is not within .005---.009 inch, remove differential case assembly and bearing shims keeping shims in order.
8. Backlash is adjusted by increasing thickness of one shim while decreasing thickness of opposite side shim by the same amount in order to maintain proper side bearing preload. Select shims to adjust backlash as follows:
a. If backlash is excessive, increase thickness of shim on gear tooth side and decrease thickness of shim on opposite side by the same amount.
b. If backlash is less than specified, decrease thickness of shim on gear tooth side while increasing thickness of opposite shim by the same amount. Each .002 inch change in shim thickness alters backlash by .001 inch.
9. Reinstall differential assembly, shims and bearing caps, torque bearing cap bolts to 40 ft. lbs., then recheck backlash and adjust as needed.
10. Ensure that ring gear teeth are clean and free from oil, then coat both drive and coast side of each tooth with suitable marking compound.

Fig. 4 Gear tooth contact pattern check:

11. Apply braking force to ``load'' ring gear, then rotate driveshaft yoke with wrench so that ring gear rotates one full revolution in each direction. Test made without ``loading'' gears will not yield satisfactory pattern, and excessive rotating of gears is not recommended.
12. Compare gear tooth pattern with Fig. 4, and correct assembly adjustments as needed.
13. When proper gear tooth contact pattern has been obtained, clean marking compound from gears.
14. Install axles and driveshaft. Refer to ``Rear Axle, Propeller Shaft & Brakes'' section for procedure.
15. Install rear cover using new gasket, then fill rear axle with suitable lubricant.