Repair materials
Number | Designation | Order number |
BR00.45-Z-1002-07A | Prussian Blue | - |
The manufacturing tolerances of the drive pinion and crown wheel are designed to guarantee proper operation when the installed dimension and gear backlash are precisely adjusted.
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As an additional check, however, the contact pattern of the gear set should always be checked.
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W33.30-0019-01
Diagram illustrates front axle AL7
Checking contact pattern
1 Coat two teeth 180° apart on the crown wheel with blue ink.
2 Spin the drive pinion forward and back while braking the crown wheel with a block of hard wood (arrow).
3 Compare the contact pattern with the example illustrated below and carry out the specified corrective measures if applicable.
W33.30-0020-01
Ideal contact pattern
Test performed under load (crown wheel braked).
An ideal contact pattern is rarely obtained in practice. It is important that the contact pattern does not extend to the outside edge of the tooth at any point on the face of the tooth.
W33.30-0021-01
Unacceptable contact patterns:
Contact at base of tooth flank
Cause:
Installed dimension of drive pinion too small.
Remedy:
Increase installed dimension between drive pinion and crown wheel slightly. Install a thicker shim for the drive pinion and repeat the backlash check again. Readjust gear backlash if necessary.
W33.30-0022-01
Contact at top of tooth flank
Cause:
Installed dimension of drive pinion too large.
Remedy:
Reduce installed dimension between drive pinion and crown wheel slightly. Install a thinner shim for the drive pinion.
W33.30-0023-01
Contact at heel of tooth
Cause:
Gear backlash badly adjusted, gear backlash too large.
Remedy:
Set crown wheel closer to drive pinion by turning the threaded rings and repeat the backlash check again.
W33.30-0024-01
Contact at toe of tooth
Cause:
Gear backlash badly adjusted, gear backlash too small.
Remedy:
Set crown wheel further away from drive pinion by turning the threaded rings and repeat the backlash check again.