Adjusting Ring Gear

Adjusting ring gear

Determining Total Shim Thickness "Stot."
(S1+S2)

NOTE:
- The ring gear must be readjusted if the transmission case, transmission side cover, taper roller bearing for differential, differential housing or drive set have been replaced.
- The drive pinion must be removed in order to determine the preload of the differential tapered roller bearings.

1. Remove adjusting shim "S1" (in transmission side cover).

2. Adjusting shim "S2" remains in the transmission case.

3. Make sure that the bearing outer races of the tapered roller bearings are well seated in the transmission case or in the transmission side cover.

4. Insert differential into transmission case and rotate several times.

5. Fit transmission side cover without seals and tighten all hexagon head bolts to 23 Nm (17 ft lb).

6. Place gauge block plate 9281 on the collar of the differential.




A Dial gauge extension (approx. 30 mm long)
B Gauge block plate 9281

7. Fasten universal dial gauge holder VW 387 with dial gauge and extension to the case and set to 0 with 2 mm preload.

8. Using a suitable tool, move differential up an down. Read off backlash on the dial gauge and note.

NOTE: Do not turn differential while measuring backlash as this will give an incorrect reading.

9. Remove adjusting shim "S2" and determine thickness using a micrometer.

10. Calculate "Stot".
- "Stot." equals thickness of adjusting shim "S2"
- Plus measured value
- Plus pressure fit of taper roller bearings

Example
Thickness of adj. shim "S2" 1.70 mm
Measured value 0.91 mm
Press fit (constant value) 0.24 mm ___________
"Stot" 2.85 mm

11. Spread calculated shim thickness "Stot" as follows.
- To start with the backlash adjustment, the thickness of adjusting shim "S1" is reduced by 0.40 mm while the thickness of adjusting shim "S2" is increased by 0.40 mm.

Example
Total shim thickness of adjusting shims S1 + S2 = 2.85 mm
Thickness Of Adjusting Shim "S1"
2.85 mm divided by 2 equals 1.425 mm minus 0.40 mm equals 1.025 mm
Thickness Of Adjusting Shim "S2"
2.85 mm divided by 2 equals 1.425 mm plus 0.40 mm equals 1.825 mm2 +

NOTE: The adjusting shims are available in thicknesses of 1.0 through 2.0 mm in increments of 0.05 mm.

- The shim thickness calculated must be rounded up or down for plausible dimensions that will not after the total shim thickness S1 and S2.

Example
Calculated shim thickness
S1 + S2 = 1.025 + 1.825 = 2.85 mm
Rounded down shim thickness
S1 + S2 = 1.00 + 1.85 = 2.85 mm