Torsional Backlash, Measuring
- Differential installed with shims "S1 " and "S2 ".
-- Install the differential with ring gear: S 1 is on the cover side, S 2 is installed in the transmission housing.
-- Install the final drive cover and tighten the four bolts to 20 Nm.
-- Complete the Crown Wheel Adjusting Tool:VW 521 (refer to Complete the as follows: ) and insert it in the differential.
-- Turn the differential five turns in both directions so that the bearings settle.
-- Attach the Dial Gauge Holder: VW 387 -6- to the final drive cover -arrow-
- Dial Indicator:VAS 6080A
- Dial Gauge Extension (8 cm plan)
- Measuring Lever:VW388
- Ring Gear Locking Sleeve:VW521/4
- Positioning Tolerance Shell:VW521/13
- Dial Indicator Holder:VW 387
-- Insert the Dial Gauge for example Dial Indicator: VAS 6080A using the Dial Gauge Extension (8 cm plan).
-- Adjust the Measuring Lever:VW 388 to the dimension -a- = 79 mm (for the ring gear 196 mm).
So that an exact torsional backlash can be measured, the pinion must be locked.
-- For this, remove the transmission housing. Refer to OVERVIEW - TRANSMISSION HOUSING .
-- Insert the Drive Axle Wedge Tool :T10161 between the output gear -1- for the spur gear unit and transmission housing.
Determine the play between the tooth flanks as follows:
-- Turn ring gear until it makes contact with a tooth flank (end of backlash travel).
-- Set the dial gauge to "0" with 2 mm pretension.
-- Turn ring gear back until lying against an opposite tooth flank (backlash).
-- Read the torsional backlash and write down the measured value.
-- Turn the ring gear 90° and repeat measurements three more times. To continue turning, remove the Drive Axle Wedge Tool:T10161 from between the output gear for the spur gear unit and the transmission housing. Refer to Torsional Backlash, Measuring .
Average Torsional Backlash, Determining
-- Add the four measured values and then divide the total by 4.
| Example: | ||
|---|---|---|
| 1. Measured value | 0.23 mm | |
| + | 2. Measured value | 0.24 mm |
| + | 3. Measured value | 0.22 mm |
| + | 4. Measured value | 0.23 mm |
| = | Total of the measured values | 0.92 mm |
- Results: the center torsional backlash is 0.92 mm: 4 = 0.23 mm
Shim Thickness "S2 ", Determining
Formula: "S2 " = "S2 *" - measured torsional backlash + specified torsional backlash
| Example: | ||
|---|---|---|
| Old shim "S 2 *" | 1.05 mm | |
| - | Measured average torsional backlash | 0.23 mm |
| + | Specified torsional backlash (desired average value for the torsional backlash) | 0.15 mm |
| = | Shim thickness "S 2 " | 0.97 mm |
Available shims "S 2 " Adjusting Shims Available for ; for the part number, refer to the appropriate Electronic Parts Information.
Shim Thickness "S 1 ", Determining
Formula: "S 1 " = "S total " - "S 2 "
| Example: | ||
|---|---|---|
| Total shim thickness "S total " for "S 1 *" + "S 2 *" | 2.26 mm | |
| - | Shim thickness "S 2 " | 0.97 mm |
| = | Shim thickness "S 1 " | 1.29 mm |
Available shims "S 1 " Adjusting Shims Available for ; for the part number, refer to the appropriate Electronic Parts Information.
-- Remove the old shims "S 1 *" and "S 2 *" and install the newly determined shims. Refer to OVERVIEW - DIFFERENTIAL .
Measurement check
-- Turn the differential five turns in both directions after installing the shims "S 1 " and "S 2 " so that the tapered roller bearings can settle.
-- Measure backlash on the circumference four times.
- Specified value: 0.15 ± 0.04 mm
- Dial Indicator:VAS 6080A
- Dial Gauge Extension (8 cm plan)
- Measuring Lever:VW388
- Ring Gear Locking Sleeve:VW521/4
- Positioning Tolerance Shell:VW521/13
- Dial Indicator Holder:VW 387
- If the torsional backlash is outside of the tolerance, then repeat the adjustment. Total shim thickness "S total " may not be changed.