Assembly & Adjustments

The following procedure requires tools from differential tool kit 8.0520 Y.

Fig. 4 Differential adjustment points:

1. Clean all parts of differential assembly, Fig. 4. Spray Molykote 321 R into drive pinion bearing housings.
2. Check that front bearing slides freely on drive pinion shaft. If not, use fine abrasive to polish shaft bearing surface until bearing just slides on.
3. Remove any burrs from front end of pinion shaft with stone.
4. Press rear bearing on pinion until fully seated.
5. Mount differential housing in vise and install front pinion bearing outer race. Install rear outer race with thrust washer. Torque tool to 103.25 ft. lbs.
6. Install pinion in housing with front and rear bearings and the measuring nut.
7. Torque to 7.2 ft. lbs. Turn pinion counterclockwise 10 revolutions. Repeat until nut no longer tightens under torque of 7.2 ft. lbs.

Fig. 5 Installing mesh setting fixture:

8. Install mesh setting fixture into differential housing, Fig. 5. Hold with bridge clamp and torque nuts to 7.2 ft. lbs. Equalize gap between fixture arms Land differential housing by checking with feeler gauges.
9. Loosen fixture plunger and make sure that plunger contacts rear face of drive pinion.
10. Place dial indicator in holder and position holder so dial indicator plunger guide rests on upper surface of plunger.
11. Adjust height of dial indicator in holder so small hand is set to 3.
12. Turn dial face to bring 0 in front of big hand.
13. Slide dial indicator holder to bring dial indicator plunger into contact with machined surface of fixture. Displacement sown by dial indicator hands indicates depth of plunger. Note value obtained.

Fig. 6 Matching reference chart:

14. Drive pinion rear face has marks for meshing distance (0-20 can be negative number) and matching reference (number preceded by letter, also found on ring gear). Note matching reference mark from pinion and refer to table, Fig. 6, to find corresponding guide number.

Fig. 4 Differential adjustment points:

15. Compare dial indicator reading with guide number. The difference between the amount dial indicator probe enters and the guide number is the thickness of shims required between rear bearing outer race and thrust washer (adjustment no. 1) Fig. 4, rounded off to nearest .05 mm (.002 inch). For example: Dial indicator figure 67 (Pinion reference - 4) - guide number 26 = 41. Use shim .40 mm (0.16 inch). Shims are available in .05, .10, .20, .30, .40, and .50 mm.
16. Remove mesh setting fixture and drive pinion.
17. Remove rear bearing outer race.
18. Reinstall thrust washer, adjustment shims determined in step 15, and bearing outer race. Tighten tool to 101.3 ft. lbs.
19. Place pinion horizontally in vise and color mark full length of one spline.
20. Place long spacer and measuring nut on pinion. Torque to 202.5 ft. lbs.
21. Set up a dial indicator on front face of drive pinion with indicator plunger extension and tip in contact with machined ace of nut and opposite marked spline.
22. Adjust height of indicator so indicator reads 1 and 0.
23. Disengage dial indicator, taking care not to lose setting, and position aside.
24. Install pinion in differential housing with front bearing and measuring nut. Torque to 7.2 ft. lbs. Turn pinion counterclockwise 10 revolutions.

Fig. 4 Differential adjustment points:

Fig. 7 Determining pinion bearing preload shim thickness:

25. Place dial indicator set-up previously set to 1 and 0 opposite marked spline with tip in contact with machined surface of measuring nut, Fig. 7. Note indicator reading. Subtract .06 mm (.002 inch). Figure calculated is thickness of spacer that will be inserted between front bearing and long spacer, (2nd adjustment), Fig. 4.

Fig. 8 Available preload shims:

26. Select shim closest in thickness to that measured, Fig. 8. For example: measured inside housing 7.86 - measured outside housing 1.00 = Difference 6.86 - 0.06. Thickness required, 6.80 mm. In this example a 6.79 mm shim would be used since a 6.80 mm shim is not available.
27. Install pinion in housing with long spacer, shim selected in step 26, and new nut. Torque to 202.5 ft. lbs. Use speed wrench to rotate pinion rapidly to seat bearings.
28. Place differential housing vertically in vise. Install mesh setting fixture and measure amount that fixture plunger is moved inward. This value should agree with the guide number with a tolerance of +.05 mm (.002 inch) and - .03 mm (.001 inch).
29. Remove fixture and stake input pinion at the 4 dimples provided.
30. Oil components and place new dimpled washer in bottom of spider gear carrier with dimples facing toward side gear.
31. Install right side gear. Install planetary gears with domed dimple washers and insert spider gear spindle taking care to align dowel holes. Press new roll pin into dowel holes as far as chamfer will allow.
32. Place ring gear flat on bench with gear teeth up.
33. Assemble in following order: dimpled washer, side gear, and assembled differential carrier. Then install retaining bolts.
34. Clamp differential in soft-jawed vise and torque bolts to 94 ft. lbs. in alternating pattern.
35. Press out oil seals from differential bearing thrust plate.
36. Press new bearings onto differential using thrust pad.