Side Bearing Preload & Ring Gear Backlash
- With pinion shaft correctly adjusted, install differential assembly into final drive housing. Coat "O" rings and threads of side bearing adjusting rings with multi-purpose grease and coat side bearings with hypoid gear oil.
- Install both adjusting rings into final drive housing until they are flush with housing. Next, adjust right side (ring gear end) adjusting ring in until ring gear meshes with pinion shaft gear with no backlash, then screw left ring in and preload slightly so that side bearings have no play. See Fig 1 .
- From this position, unscrew right adjusting ring 2 1/2 teeth, then screw in left adjusting ring 5 teeth. This should correctly set side bearing preload and ring gear backlash.
- To check ring gear backlash, rotate pinion shaft several times in both directions to settle bearings. Install docking sleeve (VW 521/4) with slotted sleeve (VW 521/7) in differential and secure with nut. See Fig 2 .
- Adjust length of backlash measuring bar (VW 388) to 3.15" (80 mm)., Attach correctly adjusted measuring bar to locking sleeve.
- Install dial indicator with .24" (6 mm) flat end extension (VW 382/10,) in indicator holder (VW 387). Bolt holder to final drive housing so that indicator is located at a right angle to backlash measuring bar.
- Turn ring gear (via pinion shaft) until measuring bar contacts dial, indicator gauge pin, then turn ring gear further until indicator shows .04" (1 mm) preload. Attach locking clamp: (VW 386) to pinion shaft. See Fig 4 . Tighten clamp screw to lock pinion shaft.
- Turn ring gear away from dial indicator until it is stopped by the locked pinion shaft, then zero dial indicator. Next, turn ring gear towards indicator until it is again stopped by pinion shaft. Read and record indicator reading. This reading is the ring gear backlash.
- Repeat backlash measurement procedure at three other points 90 degrees apart around ring gear. Add the four measurements together; then divide the total by four. The resulting sum is the average ring gear backlash, which should be .006-.010" (.15-.25 mm).
- If backlash is not within specifications, correct by turning both side bearing adjusting rings an equal amount in opposite directions so that bearing preload is not altered. Remove measuring tools.
- With backlash correct, check pinion shaft turning torque. Total pinion shaft turning torque, with differential installed, should be 14.2 INCH lbs. (1.6 N.m).
- Install side bearing adjusting ring lock plates and tighten bolts to specified torque. Install new oil seals in adjusting rings. Install final drive oil pan using a new gasket.
- Install a new torque converter oil seal into final drive housing. Install a new governor oil seal into housing with lip pointing toward governor, then install governor assembly.
NOTE:
Refer to Fig 3
for positioning of ring gear backlash measuring tools.
NOTE:
The individual backlash measurements should not vary from each other by more than .002" (.05 mm); if they do, ring gear or pinion shaft is worn or they have been improperly installed.