Adjusting Ring Gear

Total Shim Thickness "Stotal" (SUS2), Determining

NOTE:
^ Adjustment of the ring gear is only necessary if the housing for the final drive, the tapered roller bearings for the differential gear the differential gear housing or the ring gear and pinion set have been replaced. Adjustment summary.
^ To determine the total shim thickness "Stotal," the pinion must be removed or the ring gear on the differential gear housing has to be removed.
^ The tapered roller bearings for the differential gear are low friction. Therefore, the turning torque can only be used conditionally as an inspection value. Correct adjustment is only possible by determining the total shim thickness "Stotal,. "
^ Do not additionally treat new tapered roller bearings to measure turning torque. For this purpose, the bearings are already pre-treated with a special oil.

- Remove sealing ring and outer race of tapered roller bearing for left and right differential gear.
- Drive outer race of tapered roller bearing for right differential gear (cover side) in to stop without shims.
- Drive outer race of tapered roller bearing for left differential gear (housing side) in to stop without shims.
- Install differential gear in housing.
Ring gear lies on right (cover) side.
- Install cover and tighten bolts.
Tighten to: 24 Nm (18 ft lb)
- Install special tools VW 521/4 and 521/8 in differential gear housing on housing side.
- Turn cover upward.
- Place measuring plate VW 385/17 on differential gear.

NOTE: Turn differential gear several times in both directions so that tapered roller bearings settle.





- Install measuring tools.
A - Dial indicator extension, approx. 30 mm long
B - Bolt M8x45
- Place dial indicator extension in center of measuring plate.
- Set dial indicator (3 mm measuring range) to "0" with 1 mm pre-load.





- Lift differential, read play on dial indicator and record.
Example: 1.60 mm

Determining "Stotal" (S1 + S2)
"Stotal" = measurement + pre-load

Example:
Pre-load (constant value) 0.30 mm
Measurement (example) + 1.60 mm ________________________________________
"Stotal" = 1.90 mm

The total shim thickness determined (1.90 mm in the example) is divided between the two outer tapered roller bearing races as follows:

Example:
Stotal 1.90 mm
S2 (housing side) default value 1.00 mm
S1 (cover side) variable value 0.90 mm

NOTE:
^ The preset value S2* (1.00 mm) should contribute to fast ad justment of the backlash.
^ The total shim thickness "Stotal", must be maintained.
^ Shims supplied as replacement parts, refer to the parts supplier.





- Measure turning torque.
A = Torque gauge, standard commercial = 0 - 600 Ncm
Turning torque specifications
New bearings: 150-300 Nm (13-27 inch lb)
Used bearings: 30-60 Ncm (3-5 inch lb)

NOTE:
^ The tapered roller bearings for the differential gear are low friction, Therefore, the turning torque can only be used conditionally as an inspection value. Correct adjustment is only possible by determining the total shim thickness "Stotal. "
^ Do not additionally treat new tapered roller bearings to measure turning torque. For this purpose, the bearings are already pre-treated with a special oil.
^ If the ring gear and pinion set is being adjusted, a pinion adjustment (with checks) should be carried out next. Adjusting Pinion Gear