Differential Bearing Preload and Backlash Adjustment

Worksheet for calculating ring gear backlash and differential bearing preload shims






1. Install master differential bearings, Special Tool D-336, or equivalent.





2. Install differential case assembly with master bearings into the differential carrier.





3. Install dial indicator.
4. Pull differential case towards dial indicator and zero gauge. Then check travel of differential case. Move case back and fourth several times. The same reading should appear. Record amount of movement of the differential case.
5. Remove dial indicator, differential case and master bearings.
6. Install inner and outer pinion cups into differential carrier. Use special tools C-4308, D-129 and handle C-4171, or equivalents.
7. Install outer pinion bearing cone and thrust washer. Then install a new pinion seal. Use special tools D-163 and C-4171, or equivalents to install seal.





8. Install a new collapsible spacer onto pinion.
9. Install pinion with collapsible spacer into carrier.





10. Install pinion yoke onto pinion shaft. Use special tool C-3718, or equivalent to install yoke.





11. Install pinion washer and a new pinion nut. Torque the pinion nut to 285 Nm (210 ft. lbs.).
12. Check the turning torque of the pinion. The turning torque should be 2.2 Nm to 4.5 Nm (20 to 40 inch lbs.). If the reading is less than 2.2 Nm (20 inch lbs.), tighten the pinion nut in small increments. Do this until a turning torque of 2.2 to 4.5 Nm (20 to 40 inch lbs.) is reached. Do not tighten the pinion nut more than 393 Nm (290 ft. lbs.).

CAUTION: If the turning torque is more than 4.5 Nm (40 inch lbs.), the collapsible spacer has been compressed to far. The spacer must be removed and a new spacer installed.

13. Install master differential bearings Special Tool D-336, or equivalent. Remove all burrs, nicks, dirt, etc., from hubs to allow master bearings to rotate freely.





14. Install dial indicator onto the case. Measure the amount of travel of differential case.
15. Install correct shims on differential case. Use work sheet to determine correct shims. Use special tool C-4340 driver and C-4171, or equivalents handle to install bearings.
16. Install spreader (with adapters). Install dial indicator and spread case 0.010 inch.





17. With the case spread, remove dial indicator and install differential case with bearings and cups.
18. Release spreader tension and remove spreader.





19. Install bearing caps. Torque cap bolts to 88 Nm (65 ft. lbs.). Be sure that the stamping on the caps match the stamping on the carrier.





20. Install a dial indicator as shown.





21. Rock the ring gear back and forth without moving the pinion. Measure the amount of movement in the ring gear. The measurement made is called backlash. It should be between 0.005" and 0.008" inches.





22. Install output shaft bearing with special tool 0573 driver and 4171 handle, or equivalents. The driver is a two sided tool. One side is used to install the output shaft bearing, the other side is used to install the output shaft seal. When installing bearing the name on the side of the bearing must face outward (touch the driver).





23. Install new output shaft seal. Use the same driver (6573, or equivalent) used to install the output shaft bearings. The driver is a two sided tool. One side is used to install the output shaft bearing, the other side is used to install the output shaft seal.
24. Install output shafts and C-clips.
25. Clean rear cover sealing surface. Then apply new sealant and install cover and bolts. Torque bolts to 47 Nm (35 ft. lbs.).