Side Bearing Preload And Ring Gear Backlash

ADJUSTMENT - SIDE BEARING PRELOAD AND RING GEAR BACKLASH

Special Tools:










DIFFERENTIAL SIDE BEARING PRELOAD MEASUREMENT/CORRECTION

Differential side bearing preload should be measured and adjusted after the following scenarios:

- Differential case replacement
- Differential side bearing replacement
- Axle housing replacement
- Loss or replacement of side bearing snap rings

If none of these situations apply, refer to Ring Gear Backlash Measurement/Correction
.





1. Install Universal Spreader Adapter Plates (1), and Spreader (2). Install a stud into the case in the location shown. Mount Clamp to the stud, and install Post from Dial Indicator Set into the Clamp. Zero Metric Dial Indicator (3) in the location shown to measure axle housing spread
.




2. If differential side bearing cups and snap rings are removed at this point, skip to Step 6. Otherwise, expand spreader to spread axle housing no more than 0.30 mm (0.012 in.).





3. Remove both differential side bearing snap rings (1). Tag snap ring to ensure installation in original position.





4. Measure and record snap ring (2) thickness for later use.





5. Relax spreader (1) to relieve tension on axle housing.





6. Install right (pinion) side bearing cup and snap ring (1).





7. Zero dial indicator.
8. Expand spreader (1) to spread axle housing no more than 0.30 mm (0.012 in.).





9. Install left (ring gear) side bearing cup and snap ring (1).





10. Relax spreader (1) to relieve tension on axle housing.

11. Measurement showing on indicator is the axle housing retained spread. Proper differential side bearing preload is achieved with an axle housing retained spread of 0.18-0.23 mm (0.007-0.009 in.).
12. If retained spread is less than 0.18 mm (0.007 in.), increase snap ring thickness at each side in equal increments.
13. If retained spread is greater than 0.23 mm (0.009 in.), decrease snap ring thickness at each side in equal increments.

RING GEAR BACKLASH MEASUREMENT/CORRECTION

Differential Ring Gear Backlash should be measured and adjusted after the following scenarios:

1. Ring and pinion gear replacement
2. Pinion head bearing replacement
3. Pinion depth (shim) adjustment
4. Differential case replacement
5. Differential side bearing replacement
6. Axle housing replacement

NOTE: If Spreader is installed, make sure tension on axle housing is relieved.






7. Install Universal Spreader Adapter Plates (1), and Spreader (2). Install a stud into the case in the location shown. Mount Clamp to the stud, and install Post from Dial Indicator Set into the Clamp. Zero Metric Dial Indicator (3) in the location shown to measure axle housing spread
.
8. Rotate ring gear one direction to take up clearance to pinion. Verify indicator tip is in contact with ring gear and zero indicator. Rotate ring gear back and forth and record measurement. Ring gear backlash should be 0.13-0.18 mm (0.005-0.007 in.). Verify back lash measurement in four positions.





9. If backlash measurement is less than 0.13 mm (0.005 in.), it is necessary to decrease the snap ring thickness on the ring gear (left) side, and increase the thickness on the pinion (right) side.
10. If backlash measurement is greater than 0.18 mm (0.007 in.), it is necessary to increase the snap ring thickness on the ring gear (right) side, and decrease the thickness on the pinion (left) side.

GEAR CONTACT PATTERN

The ring gear and pinion teeth contact patterns will show if the pinion depth is correct in the housing. It will also show if the ring gear backlash has been adjusted correctly. The backlash can be adjusted within specifications to achieve desired tooth contact patterns.

1. Apply a thin coat of hydrated ferric oxide or equivalent to the drive and coast side of the ring gear teeth.
2. Wrap, twist, and hold a shop towel around the pinion yoke to increase the turning resistance of the pinion. This will provide a more distinct contact pattern.
3. With a boxed end wrench on a ring gear bolt, rotate the differential case one complete revolution in both directions while a load is being applied from shop towel.

The areas on the ring gear teeth with the greatest degree of contact against the pinion teeth will squeegee the compound to the areas with the least amount of contact. Note and compare patterns on the ring gear teeth to Gear Tooth Contact Patterns chart (Figure 12) and adjust pinion depth and gear backlash as necessary.




Figure 12 - Gear Tooth Contact Patterns