Ring Gear, Adjusting

Ring gear, adjusting
(Adjusting differential)





Special tools and equipment
^ VW 295 Drift
^ VW 382 Measuring device
^ VW 385 Universal measuring set
^ VW 387 Universal dial gauge bracket
^ VW 388 Adjustable measuring lever
^ VW 402 Thrust plate





Special tools and equipment
^ VW 459 Installation and removal tool
^ VW 521 Ring gear adjusting device
^ 30-205 Thrust plate
^ 30-505 Mandrel
^ 3062 Press disk

It is necessary to readjust the ring gear when:
Transmission housing, final drive cover, differential tapered roller bearings, differential housing or the ring gear and pinion
are replaced.
Refer to; Adjustment overview

Determining total shim thickness "S_total"(S1 plus S2).
(Adjusting differential tapered roller bearings)
^ Pinion shaft removed!
^ On transmissions with an oil pump the oil pump must be removed.
- Pull out flange shaft oil seal with VW 681.
- Remove differential tapered roller bearing outer race and take out shims.





- Drive tapered roller bearing outer race with shim S2 into transmission housing. Use shim S2*, 1.20 mm thick, (2 shims of 0.60 mm) to perform measurements.

Note: As a test requirement, a shim S2 of 1.20 mm is temporarily installed. It is referred to as S2* below. After backlash is determined, S2* it is replaced with final shim S2.





- Press tapered roller bearing outer race without shim into differential housing cover.
- Install differential in housing without speedometer drive wheel.
The ring gear side is the left-hand side (cover side).
- Install cover and tighten bolts to 25 Nm.
- Turn transmission so that differential housing cover is facing up.
- Turn differential 8 turns in both directions, so that tapered roller bearings settle.
- Place measuring plate VW 385/17 on differential.





- Mount measuring tools.
- Place dial indicator extension on center of measuring plate VW 385/17.
- Set dial gauge (3 mm range) to zero with 2 mm preload.
- A-: 30 mm extension





- Move differential up and down (direction of arrow) with special tool VW 521.
- Read play from dial indicator gauge.

Example:
0.62 mm
"S_total"= S2* + dial gauge reading + preload





Example:

Determining shim "S1" thickness

Note:
^ The temporary shim S1* is replaced with the final shim S1 after backlash is determined.
^ The total shim thickness "S_total" remains unchanged.

S1*+ S_total - S2





Example:

Note: Determine shims according to parts Supplier.

Adjusting backlash
^ Pinion shaft installed with S3 and S4
^ Differential with ring gear: S1 is on cover side, S2* is installed in transmission housing.

- Install final drive cover and tighten bolts to prescribed torque.
- Turn differential several times in both directions so that tapered roller bearings settle.





- Mount measuring tools.

Note: Use dial indicator extension VW 382/10 (6 mm flat).

- Set measuring lever VW 388 to dimension "a" = 79 mm.
- Turn ring gear to stop. Set dial indicator to zero, turn ring gear back and read backlash. Note reading.
- Repeat measurement three times, turning ring gear through 90°- each time. Add four results and calculate average backlash.