Spur Gear Tapered Roller Bearing Pre-Load, Determining
Determine the new adjusting shim S5
This adjustment is required when the following components are replaced:
- Transmission cover
- Center differential housing
- End shield
- Spur gear
- Tapered roller bearing on the spur gear
Special tools and workshop equipment required
- Magnetic Plate 50 mm Dia. VW 385/17 from the Universal Measuring Tool VW 385
- Dial Gauge Holder VW 387
- Crown Wheel Adjustment Device VW 521
- Dial Gauge Extension from the Dial Gauge Adapter 2066
- The outer race / tapered roller bearing for the gear wheel mounting is installed inside the transmission cover.
- The outer race / tapered roller bearing with adjusting shim for the gear wheel mounting is installed inside the gear carrier. A 0.85 mm adjusting shim S5 * must be used (part number 012 409 387 ED) for measuring.
For the initial measurement, an adjustment shim S5 with a thickness of 0.85 mm is inserted. It is designated as S5 * in the following. After determining the bearing pre-load, S5 * is replaced by final S5 .
-- Install the spur gear in the transmission cover.
Install the gear carrier on the transmission cover as follows:
- Installed position: the tab -arrow A- on the gear carrier must installed into the opening -arrow B- inside the transmission cover.
-- Attach the center differential housing -C- to the transmission cover using the bolts -A-, -B- and -arrows- (quantity: 5).
Not all versions have the double bolts -B- ; allocation.
-- Then set the transmission cover with the attached center differential housing in vertical position making sure the center differential housing is facing downward.
-- Install measuring tools.
-- Attach the VW 387 in the hole in the transmission cover using the screw -B- and nut.
-- Place VW 387 on center of VW 385/37.
-- Set dial gauge (3 mm measuring range) to >>0<< with 2 mm preload.
-A- VW 387 from the 2066
-- Move the spur gear up and down using the VW 521.
-- Read play on dial gauge.
Example:
0.26 mm
Example:
| Installed shim S5* | 0.85 mm |
| Measurement result (example) | + 0.26 mm |
| Preload (constant value) | + 0.10 mm |
| Thickness of adjustment shim S5 | = 1.21 mm |
Allocate adjustment shims.
-- The thickness of the shim S5 in this example is 1.21 mm.