Pinion Shaft, Adjusting

Pinion shaft, adjusting
Special tools and equipment





^ VW 385 Universal mandrel





^ VW 540 Engine and transmission holder
^ Torque gauge 0 - 600 Ncm, commercially available
^ Deep socket insert, 36 mm
It is only necessary to readjust the pinion shaft as described below when the ring gear and pinion or pinion shaft tapered roller bearings or rear axle housing have been replaced.Refer to Adjustment overview.

Determining thickness of shim "S3"
(Adjusting pinion shaft tapered roller bearings preload).
- Insert both tapered roller bearing outer races without shims into housing.
- Insert drive pinion in transmission housing with large tapered roller bearing inner race but without spacer sleeve.

WARNING!: Wear protective gloves!





- Heat small tapered roller bearing inner race to approximately 100°C and install on pinion shaft.
- Install driveshaft flange and tighten hex nut for flange.
Note:
^ Install new tapered roller bearings as supplied and do not use any additional oil.
^ The spacer sleeve should only be installed by the subsequent frictional torque adjustment (Shim S3 has already been determined).





A - Torque gauge, 0 - 600 Ncm, commercially available
B - Deep socket insert, 36 mm AF





Setting friction torque

Note: Use reducer 3/4" to 1/2" if necessary.





- Set universal mandrel VW 385/1 setting ring to dimension -a- = 60 mm.
- Set sliding positioning ring to dimension -b- = 55 mm.





- Assemble universal measuring tool as shown in illustration. Measuring gauge extension VW 385/15 = 9 mm. Set universal gauge VW 385/30 to Ro = 57.50 mm.
- Set dial gauge (3 mm measuring range) to zero with 2 mm preload.
- Turn pinion shaft at least 8 turns in both direction so tapered roller bearings settle.





- Place end measuring plate on face of pinion shaft.





- Remove master gauge and insert measuring tool in housing.
- Install rear final drive cover and tighten 4 bolts.
- Using sliding setting ring to pull 2nd centering disc outward until mandrel can still just be turned by hand.





- Turn checking mandrel until dial gauge extension makes contact with end measuring plate and indicates maximum deflection (return point). Measured value is dimension "e".

Example:
1.60 mm (red number range)

Determining shim "S3" thickness
S3 = e - r
e - Calculated value (max deflection)
r - Dimension (given in 1/100 mm on ring gear)

Example:





Different tolerances make it possible to select the exact thickness of shim(s) required.





Table of shims

Note: Determine shims according to parts Supplier.

- Remove universal measuring device.
- Remove pinion shaft and large tapered roller bearing outer race and install calculated shim S3 and spacer sleeve.
- Insert small tapered roller bearing inner race and tighten nut for pinion shaft to prescribed friction torque

Note: Increase tightening torque slowly and check friction torque at regular intervals. If the prescribed friction torque is exceeded, the spacer sleeve must be replaced and the adjustment repeated. A spacer sleeve which has been compressed too much cannot be reused.





Set friction torque as follows:

Checking dimension "r"
- Turn pinion shaft at least 8 turns so tapered roller bearings settle.





Insert universal measuring tool and measure dimension "r".
With correctly selected shims and reading counter-clockwise (red number range), dial gauge must indicate value of noted deviation "r" within a tolerance of + 0.05 mm.
- After nut for pinion shaft is secured measure radial run-out on driveshaft flange and mark.