Drive Pinion, Adjusting

Drive pinion, adjusting
Special tools and workshop equipment required





- VW 385 Universal measuring tool





- VW 540 Engine and gearbox support

Notes:
^ Before adjusting the drive pinion adjust the ring gear (ascertain total shim thickness "S" for shims "S1 " + "S2').
^ Re-adjustment of the drive pinion is only necessary if the final drive set, taper roller bearing for drive pinion or housing for final drive is replaced; Refer to Differential Adjustments.
^ Do not additionally oil new taper roller bearings for frictional torque measurement. The bearings have already been treated with special oil by the manufacturer.

Ascertaining shim "S3" thickness
(Setting preload of taper roller bearing for drive pinion)
- Clamp final drive into assembly bracket.
- Insert both outer races for the taper roller bearing without shims into the housing; Refer to Fig. 9 and Fig. 10





- Insert drive pinion without spacer sleeve.
- Heat inner race for taper roller bearing to approximately 100°C and install onto drive pinion.

WARNING!: Wear protective gloves!

Notes:
^ Only install spacer sleeve for final frictional torque measurement (after determining shim "S3').
^ Install new taper roller bearings in delivery condition and do not oil additionally.

- Mount flanges for drive shaft and tighten hexagon nut for the flange





A - Torque gauge, commercially available, 0 to 600 Nm
B - Socket, A/F 36





- Tighten drive pinion nut until the following frictional torque is obtained.





- Set adjustment ring of universal mandrel VW 385/1.
^ Distance a = 60 mm
- Set sliding adjustment ring.
^ Distance b = 55 mm





- Assemble universal mandrel as illustrated.
^ Dial indicator extension VW 385/15 = 9 mm long
- Set universal master gauge VW 385/30.
^ Ro = 57.50 mm
- Set dial indicator (3 mm measuring range) to "0" with 2 mm preload.
- Turn drive pinion 8 turns in both directions so that the taper roller bearings settle.





- Place end measuring plate VW 385/33 onto drive pinion head.





- Remove master gauge and insert measuring mandrel in the housing.
^ The centering disc for VW 385/3 faces towards cover for final drive
- Install cover for final drive and tighten 4 bolts.
- Using the adjustable ring, move 2nd centering disc out as far as possible so that the mandrel can still just be turned by hand.





Determining measurement "e"
- Turn mandrel until the dial indicator point touches the end measuring plate on pinion shaft head, then measure maximum deflection (return point). The measured value is dimension "e" (in red range).
^ Measurement in following example: "e" = 1.60 mm

Note: Dimension "e"is required to determine thickness of shim "S3".

- Then, (after removing universal mandrel) check again that the dial indicator, with master gauge VW 385/30 fitted, indicates "0" with 2 mm preload, otherwise repeat the measurement.

Determining shim thickness "ST'
Formula:
"ST' = "e" - "r"
e = determined value
r = deviation (marked on ring gear in 1 1100 mm)

Example:
Determined value "e" 1.60 mm
- Deviation T' 0.42 mm
= Thickness of shim "S3" 1.18 mm
- Determine shim(s) as accurately as possible from table. Part numbers
Refer to Part Supplier





The following shims are available for "ST"

- Remove universal mandrel.
- Remove drive pinion and outer race for large taper roller bearing and reinstall with calibrated shims "S3" and spacer sleeves onward.
- Insert inner race for small taper roller bearing and tighten drive pinion nut until specified frictional torque is achieved; Refer to Fig. 15 .

Notes:
^ Do not additionally oil new taper roller bearings for frictional torque measurement. The bearings have already been treated with special oil by the manufacturer.
^ Only increase tightening torque slowly and read off frictional torque frequently. If the specified frictional torque is exceeded, the spacer sleeve must be replaced and the adjustment repeated. It is not possible to re-use a spacer sleeve that has been excessively compressed.





- Set to following frictional torques:

Performing check measurement
Checking dimension "r"





- Turn drive pinion 8 turns in both directions so that the taper roller bearings settle.
- Insert universal mandrel and perform check measurement.
^ If the shims have been correctly selected, the dial indicator, reading counter clockwise (in red range), will show the deviation T' within a tolerance of � 0.05 mm
- Peen drive pinion nut with a punch.
- The radial run-out at flange for drive shaft must always be measured and marked.