Ring and Pinion Gear Set, List of Adjustments

General Notes:
- Careful adjustment of drive pinion and ring gear is essential for long life and quiet running of the final drive. During production, the drive pinion and ring gear are matched and checked on a special testing machine to ensure proper contact pattern and quiet running in both directions of rotation.
- The position of quietest running is determined by moving the drive pinion in an axial direction, with the ring gear being constantly raised out of zero-play meshing to a point where the torsion backlash varies within a specified tolerance.
- The deviation "r" is measured in relation to the master gauge R0 for the drive gear sets supplied as service parts and this value is inscribed on the outer circumference of the ring gear. The drive gear set-drive pinion and ring gear-must always be replaced together.






Pinion And Ring Gear Set, Adjustment And Marking
Gear sets supplied as service parts:
1. Marking "0937" indicates:
Oerlikon drive gear set with the ratio 37:9 (4.111:1)
2. ID number of matched drive gear set (e.g. 312)
3. Deviation "r" measured against master gauge of special test machine used in production.
- Deviation "r" is stated in 1/100 mm.
- Example: "25" means r = 0.25 mm
Ro. Length of master gauge used on special test machine.
Examples:
- Ro for 170 mm diameter ring gear = 54.95 mm
- Ro for 180 mm diameter ring gear = 59.65 mm
R. Actual distance between ring gear shaft and face end of drive pinion at the point of quietest running for this particular matched gear set
Vo. Hypoid offset






Ring Gear/Sets Used In Production
Data that is not required for series production is crossed out with an "X" in the illustration.
Po = Setting used in series production

CAUTION:
- In series production the position of the pinion is determined by dimension Po (center of ring gear to rear face of pinion). Deviation "r" and the matching number of the gear set are not inscribed on the ring gear.
- Because the deviation 'r' is unknown, an actual measurement must be carried out before removing the pinion when parts that directly affect the installation position of the drive pinion are replaced. Refer to "Pinion, Determining Installation Position (Actual Measurement)" as shown below.






1) If the transmission housing is replaced, the input shaft must also be adjusted.

List Of Adjustments
When repairing the transmission, it is only necessary to adjust the ring gear, the pinion, or both, when parts have been replaced that directly affect the final drive setting. The following table is be used to determine what is required and avoid carrying out unnecessary adjustments.

Pinion, Determining Installation Position (Actual Measurement)
This operation is required only if deviation r is not inscribed on the ring gear, and parts that directly affect the installation position of the drive pinion are to be replaced.

These are..
- Tapered roller bearings for pinion and transmission housing

Removing Differential
- Set up universal measuring bar, as described at "Pinion Adjusting", install into transmission housing and measure difference relative to R0 (max. deflection/reading in red numerical range).

The measured value corresponds to the deviation r. Note the reading.

- After replacing parts, drive pinion should be adjusted as described at "Pinion Adjusting". The measured deviation "r" should be used when determining thickness of shim S3.

Recommended Sequence For Adjusting Ring Gear And Pinion
When the ring gear and pinion have to be adjusted, the following sequence of operations is recommended to avoid unnecessary work:
1. Determine total shim thickness Stotal (S1 + S2) needed for the specified preload of the differential tapered roller bearings.
2. Determine total shim thickness Stotal (S3 + S4) needed for the specified preload of the tapered roller bearings for the pinion with hollow shaft
3. Divide total shim thickness Stotal into S3 and S4 so that the dimension from the center of the ring gear to the end face of the pinion corresponds to the installation dimension R determined in production.
4. Divide total shim thickness Stotal into S1 and S2 to achieve the specified backlash between the ring gear and the pinion.

The purpose of the adjustment is to set the ring gear and pinion to re-create the quietest running position, as determined on the special testing machine used in production.

The maximum care and cleanliness during all removal and installation work and measurement operations are essential for achieving satisfactory results.





Position Of Shims
S1 - Shim for ring gear in transmission housing cover
S2 - Shim for ring gear in transmission housing
S3 - Shim for pinion in transmission housing
S4 - Shim for pinion in transmission cover