Ring Gear Backlash Adjustment

Place shims determined for pinion adjustment between transmission case and final drive case. Install final drive to transmission and tighten all mounting bolts to specifications. Install differential assembly into case, install side covers with shims on ring gear side and tighten all bolts to specifications.
Turn differential in both directions several times to settle bearings. Install Dial Indicator (VW 388) and set to 3.1" (78.7 mm). Engage parking lock, turn ring gear by hand against stop and set dial indicator to zero.
Keep pinion from turning and turn ring gear back to stop. Read amount of backlash. The measured backlash must be within specification:
- Getrag Pinion: .006-.008" (.15-.20 mm).
- Hurth Pinion: .008-.010" (.20-.25 mm).
The positioning of shims is determined by the following:
- Ring gear side: Take total shim thickness ("S total", multiply by .026" (.66 mm). The result is the correct shim amount to be placed on ring gear side ("S1").
- Opposite ring gear side: Subtract ring gear side ("S1") from total shim thickness ("S" total) the result is ("S2") the amount of shims placed opposite ring gear side.
Remove side covers and position shims as previously determined. Tighten side covers. Measure backlash. If not within specifications, change shim "S1" and "S2" until within specification. Check backlash at 4 places by turning ring gear 90 degrees each time. The 4 measurements must not deviate more than .002" (.05 mm).