Ring gear, adjusting: Notes
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(Adjusting differential)
Special tools, testers and auxiliary items required
- Drift VW 295
- Dial gauge extension VW 382/10
- Magnetic plate VW 385/17
- Dial gauge holder VW 387
- Measuring lever, adjustable VW 388
- Pressure plate VW 402
Special tools, testers and auxiliary items required
- Punch VW 408 A
- Ring gear adjustment device VW 521
- Sleeve 30 - 14
- Thrust piece 2050
- Torque wrench V.A.G 1331
- Dial gauge
- Dial gauge extension 30 mm
A new ring gear adjustment is required when the following components have been replaced:
Transmission housing, final drive cover, differential tapered roller bearings, differential housing or the gear set
Adjustment overview → Adjustment overview
Determine total shim thickness " S total " for adjustment shims " S 1 " + " S 2 "
(Setting preload of taper roller bearing for differential)
- Drive pinion removed.
- If only the tapered roller bearing for differential has been replaced, ring gear can be removed from differential housing. Drive pinion then does not need to be removed.
- Remove flange shaft sealing rings.
- Remove outer races/tapered roller bearings for differential and remove adjustment shims → Differential, disassembling and assembling .
Fig 3: Driving Outer Race For Right Tapered Roller Bearing Together With Shim Into Differential Housing
- Drive outer race for right tapered roller bearing together with shim " S 2 " into differential housing. Use a shim " S 2 * " with a 1.30 mm thickness for measurement purposes (2 shims with 0.65 mm).
NOTE:
- For the initial measurement, an adjustment shim " S 2 " with a thickness of 1.30 mm is inserted. It is designated as " S 2 * " in the following. After determining backlash, " S 2 * " is replaced by final " S 2 ".
- Pressing outer race for tapered roller bearing without shim " S 1 " into final drive cover.
- Insert differential into transmission housing. Ring gear is located on left side in front of final drive cover.
- O-ring is inserted in final drive cover.
- Install final drive cover with 4 screws (24 Nm).
- Turn transmission so that final drive cover faces upward.
- Turn differential 5 turns in both directions so that the taper roller bearings settle.
- Place magnetic plate VW 385/17 on differential.
- Assemble measuring tool, use 30 mm dial gauge extension.
- Set gauge (3 mm measuring range) - A - to "0" with 2 mm pre-load.
NOTE:
- Tip of dial indicator must be positioned on the center of the differential.
- Lift differential without turning it, read backlash on dial indicator and note.
- Measured value in following example: 0.62 mm
NOTE:
- To raise differential, secure special tools VW 521/4 and VW 521/8 at right on differential (housing side).
- If measurement is repeated, differential must first be rotated 5 complete revolutions in both directions again to seat tapered roller bearing.
Formula: " S total " = " S 2 * " + measured value + bearing preload
| Example: | ||
|---|---|---|
| Inserted shim(s) " S 2 * " | 1.30 mm | |
| + | Measured value | 0.62 mm |
| + | Bearing preload (constant) | 0.30 mm |
| = | Total shim thickness " S total " for " S 1 " + " S 2 " | 2.22 mm |
Determining thickness of adjustment shim " S 1 * "
NOTE:
- Initial shim " S 1 * " is replaced with final shim " S 1 " after backlash has been determined.
- The total shim thickness " S total " remains unchanged.
Formula: " S 1 * " = " S total " - " S 2 * "
| Example: | ||
|---|---|---|
| Total shim thickness " S total " for " S 1 " + " S 2 " | 2.22 mm | |
| - | Inserted shim(s) " S 2 * " | 1.30 mm |
| = | Thickness of adjustment shim " S 1 * " | 0.92 mm |