Ring Gear, Adjusting

Adjusting Differential
- The ring gear must be adjusted only if the following components have been replaced:
Final drive housing, final drive cover, tapered roller bearings for differential, differential housing or gear set
- Refer to "List of Adjustments".

Determining Total Shim Thickness Stotal (S1 + S2)
(Adjusting preload of tapered roller bearings for differential)
Pinion removed
- Remove seal and outer races for differential tapered roller bearings, and remove shims. Refer to "Disassembing and Assembling/Overview" at Final Drive, Differential. Service and Repair
- Drive in tapered roller bearing outer races, without shims, as far as possible. Refer to "Disassembing and Assembling/Overview" at Final Drive, Differential. Service and Repair
- Install differential in housing.

The ring gear is on the right-hand side (cover side).

- Install cover and tighten bolts in diagonal pattern to 25 Nm (18 ft lb), with cover facing upward.
- Install measuring tools.
A = Dial indicator extension approx. 30 mm long
B = M8 x 45 hex bolt
- Set dial indicator (3 mm range) to zero with preload of 1 mm.






- Move differential up and down; read and record play on dial indicator.

Example: 1.60 mm

WARNING! Do not turn the differential when performing measurement otherwise the bearings will settle and the measurement will be incorrect.

Determining Stotal (S1 + S2)
Stotal = Dial indicator reading + preload






- Install calculated total shim thickness (2.00 mm in example) behind tapered roller bearing outer race in final drive housing (S2 side).






- Measure friction torque.
- A = Commercial torque gauge, 0.600 Ncm (0.1 in lb).






These friction torques should be set

Note: When re-adjusting the gear set, the drive pinion adjustment with check measurements should now be carried out. Refer to "Pinion, Adjusting" at Rear Final Drive, Ring and Pinion Adjusting. Adjustments

Adjusting Backlash
Pinion installed with shim S3
Differential: Stotal (-S- + S2) installed on housing side.

- Rotate differential several times in both directions to enable tapered roller bearings to settle.






- Install measuring tools.
- Use dial indicator extension VW 392/10 (6 mm flat).
Set measuring lever to -a- = 79 mm.
- Turn ring gear as far as stop; set dial indicator to zero.
- Turn ring gear back and take reading of backlash. Note reading!
- Repeat measurement three times, turning ring gear 90° for each measurement. Add together four readings and calculate average backlash.

CAUTION! If the individual readings obtained during this measurement differ by more than 0.06 mm from each other, either the ring gear or the drive gear set itself is out of alignment. Check installation work, replace drive gear set if necessary.


Determining Average Backlash






Example


Determining Thickness Of Shim S1
(Ring Gear Side)






Backlash/Shim Chart 1 of 3






Backlash/Shim Chart 2 of 3






Backlash/Shim Chart 3 of 3

Example:
- Average backlash = 0.69 mm
- S1 from table = 0.78 mm






These shims are available

Determining Thickness Of Shim S2
(Opposite ring gear)
S2 = Stotal - S1






Example






These shims are available
- Install selected shim, S1 on ring gear side, S2 opposite ring gear.

Checking Measurements
- Measure backlash four times around circumference; backlash should be 0.12-0.22 mm.

CAUTION! The individual measurements should not differ by more than 0.05 mm.