Ring Gear: Adjustments

1. Preload (expand) rear axle housing using expanding device as follows:





a. Secure expanding device (058) on rear axle housing, by tightening the collared bolts (arrows) securely to 50 Nm.





b. Turn the straight surface (arrow) of the thrust piece downwards.
c. Screw in threaded shaft (058a) by hand, until the thrust piece abuts the tapered roller





d. Place contact arm (059) on expanding device for expanded dimension measurement and press against the two pins from below
- Set dial gauge on "0. with 3 mm preload
- The stop pin (arrow) of the contact arm must abut the bearing surface of the rear axle housing





e. Screw in the threaded shaft (058a) of the expanding device until the rear axle housing has reached the specified expanded dimension of 0.11-0.17 mm

CAUTION: Do not exceed 0.17 mm when expanding center piece

f. Remove contact arm (059)
2. Insert left locking ring (29)
- Install the locking ring which was removed and marked previously in order to achieve the basic preload of the rear axle housing.
3. Release load on rear axle housing





4. Measure expanded dimension (expansion) of rear axle housing again using contact arm (059)
- If the expanded dimension is outside the specified value of: 0.11-0.17 mm, note this value for later adjustment procedures
- Remove contact arm (059).
5. Measure gear backlash between drive pinion and crown wheel and correct if necessary as follows:





a. Install gear backlash measuring device (037) with dial gauge in the right-hand bore of the differential housing and clamp securely.
b. Set dial gauge on "0" with 3 mm preload.
c. Hold the drive pinion securely at the joint flange and press the crown wheel upwards and downwards alternately, reading off the gear backlash.
d. Carry out the measurement four times, always turning the crown wheel through a further 90° each time.

NOTE:
^ The adjustment of the tapered roller bearings and the gear set is in order if the expanded dimension (expansion) of the rear axle housing and the gear backlash are within the range of 0.08-0.14 mm
^ If these values are not achieved, the adjustment must be repeated with suitably thicker or thinner locking rings

e. Remove gear backlash measuring device.
f. If either measurement is incorrect proceed as shown below:

Example 1
Measurement:
Gear backlash correct, but the expanded dimension of the rear axle housing is too small, e.g. measured expanded dimension value is 0.05 mm.

Correction:
Fit a 0.05 mm thick. locking ring on both sides, the gear backlash can change slightly in the process.

Example 2
Measurement:
Expanded dimension correct, but the gear backlash is too large.

Correction:
A locking ring which is thinner by the missing amount is to be installed on the left assembly side.
A locking ring which is thicker by the missing amount is to be installed on the right assembly side (crown wheel side).
Proceed in the reverse order if the gear backlash is too small.
g. The adjustment of the tapered roller bearings and the gear set is in order if the expanded dimension (expansion) of the rear axle housing and the gear backlash is within the range of the specified values