Adjusting Preload Spur Gear Bearings

Adjusting the preload of the spur gear taper roller bearings

Adjusting spur gear II (intermediate gear)





1. Determine and record dimension "a" (e.g. 45.90 mm).





2. Fit complete spur gear II and determine dimension "b" (e.g. 44.65 mm). Record measured value.

3. Determine shim thickness by deducting dimension "b" from dimension "a" and adding a constant value of 0.22 mm (preload and thickness of compressed gasket).

NOTE: The constant value is 0.22 mm for all transmissions.

Example
Dimension "a" e.g. 45.90 mm
Dimension "b" e.g. -44.65 mm ____________
1.25 mm
Constant +0.22 mm _____________
Shim thickness 1.47 mm

NOTE: Always round shim thickness up or down to the nearest 0.05 mm figure.


Adjusting spur gear I (drive gear)

1. Remove intermediate plate.

2. Remove adjusting shim.

3. Remove spur gear II (intermediate gear) for measurement.

4. Bolt up cover with intermediate plate (but without gasket).
- Tighten all screws and bolts to: 23 Nm (17 ft lb).

5. Internal puller (e.g. Schrem 20 - 30) into spur gear teeth.

6. Fit dial gauge holder VW 387 with dial gauge and zero out dial gauge with a preload of 2 mm.





7. Move spur gear I up and down on internal puller and read off play on dial gauge (e.g. 1. 18 mm).

NOTE:
- Do no turn or tilt the spur gear when measuring the clearance.
- Repeat measuring process several times.

8. Determine shim thickness.
- Measured value plus 0.20 mm (preload and thickness of compressed gasket) equals shim thickness

NOTE: The constant value is 0.20 mm for all transmissions.

Example
Measured value 1.18 mm
Constant value +0.20 mm _____________
Shim thickness 1.38 mm

9. Fit a shim of the determined thickness (1.38 mm in our example).

NOTE: Always round shim thickness up or down to the nearest 0.05 mm figure.