Differential Carrier Bearing Preload Adjustment 9.5, and 9.5LD Inch Axles
Tools Required
| • | J 22779 Side Bearing Backlash Gage |
| • | J 24429 Side Bearing Backlash Spanner |
Important:
• Ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used. • The drive pinion bearing preload must be within specifications before the differential side bearing preload adjustment can be performed. • The differential side bearings must be initially preloaded in order to determine the backlash of the gear set. After the backlash is set, the final bearing preload is set.
- Remove the differential assembly, if necessary.
- Measure the rotating torque of the drive pinion bearing using an inch-pound torque wrench.
- If the rotating torque of the drive pinion is less than 1.7 N·m (15 lb in) for new bearings or 1.1 N·m (10 lb in) for used bearings, tighten the pinion in small increments until the specified rotating torque is obtained.
- If the rotating torque of the drive pinion is greater than 3.4 N·m (30 lb in) for new bearings or 2.3 N·m (20 lb in) for used bearings, remove the drive pinion and replace the collapsible spacer and re-install the drive pinion. Refer to Drive Pinion Bearings Replacement.
- Install the differential assembly, if necessary.
- Support the differential assembly in order to prevent the differential assembly from falling out of the axle housing.
- Slide the differential case assembly towards the right side axle housing until the ring gear contacts the drive pinion.
- While holding the ring gear against the pinion, turn the differential bearing adjuster nut out from the axle housing using the J 24429 until it contacts the differential side bearing.
- Turn the adjuster nut out from the axle housing an additional 2 slots using the J 24429 in order to obtain the initial backlash adjustment.
- Install the adjuster nut lock and the adjuster nut lock bolt.
- Remove the left side differential bearing cap bolts.
- Remove the left side differential bearing cap.
- Install the J 22779 into the left side axle housing between the differential bearing bore and the differential bearing cup.
- Tighten the knob of the J 22779 until there is moderate drag when the J 22779 is moved.
- Remove the J 22779 .
- Measure the J 22779 in 3 locations.
- Calculate the average of the 3 measurements.
- Select a service shim of approximately the same thickness to install into the axle housing.
- Install the service shim into the axle housing between the differential bearing bore and the differential bearing cup.
- Install the left side differential bearing cap.
- Install the left side differential bearing cap bolts.
- Remove the differential bearing adjuster nut lock bolt.
- Remove the differential bearing adjuster nut lock.
- Firmly tighten the differential bearing adjuster nut using the J 24429 in order to force the differential case assembly into solid contact with the service shim.
- Rotate the pinion several times in order to seat the bearings.
- Loosen the differential bearing adjuster nut using the J 24429 until the nut is free from the differential side bearing.
- Tighten the differential bearing adjuster nut using the J 24429 until the differential bearing adjuster nut contacts the bearing.
- Once the right differential bearing adjuster contacts the differential bearing, tighten the differential bearing adjuster nut using the J 24429 the following additional amounts:
- Install the right differential bearing adjuster nut lock.
- Install the right differential bearing adjuster nut lock bolt.
- Tighten the bearing cap bolts.
- Tighten the differential bearing adjuster nut lock bolt.
- Measure the drive pinion and differential case side bearing preload using an inch-pound torque wrench.
- Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in Step 2, from the drive pinion and differential case bearing preload, measured in Step 33.
- If the differential case side bearing preload is not within specifications, use the J 24429 and turn the differential side bearing adjuster nut in or out one slot at a time in order to increase/decrease the side bearing preload.
- Once the differential side bearing preload is correct, measure the drive pinion to differential assembly backlash and adjust, if necessary. Refer to Backlash Adjustment.
Caution: To prevent personal injury and/or component damage, support the differential case when removing the case from the axle housing. If the case is not supported, the differential case could fall and cause personal injury or damage to the differential case.
Specification
The rotating torque of the drive pinion should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.3 N·m (10-20 lb in) for used bearings.
Important: Do not force the ring gear into contact with the drive pinion.
This is the ZERO backlash point.
If the ZERO backlash cannot be obtained, turn the differential bearing adjuster nut into the axle housing using the J 24429 until the ring gear fully contacts the drive pinion to obtain the ZERO backlash.
Important: Over-tightening may spread the axle housing and result in incorrect shim selection.
The resulting value is the shim thickness required in order to set the initial backlash of the differential assembly.
Verify the thickness of the service shim using a micrometer.
Tighten the differential bearing cap bolts finger-tight. Do not torque the bolts at this time.
Tighten
| • | For new bearings, tighten the differential bearing adjuster nut an additional 3 slots. |
| • | For used bearings, tighten the differential bearing adjuster nut an additional 2 slots. |
Do not torque the bolt at this time.
Notice: Refer to Fastener Notice in the Preface section.
Tighten
Tighten the bearing cap bolts to 85 N·m (63 lb ft).
Tighten
Tighten the differential bearing adjuster nut lock bolt to 26 N·m(19 lb ft).
Rotate the pinion several times to ensure the bearings have seated.
Specification
The rotating torque of the drive pinion and differential case bearings should be 0.57-1.13 N·m (5-10 lb in) greater than the rotating torque of the drive pinion measured earlier.
Record the measurement.
Multiply the value obtained by the axle ratio.
Specification
The differential case side bearing preload should be 1.7-4.0 N·m (15-35 lb in).
Differential side bearing shims are available in the following sizes:
Shim Sizes
| • | 5.59 mm (0.220 in) |
| • | 5.64 mm (0.222 in) |
| • | 5.69 mm (0.224 in) |
| • | 5.74 mm (0.226 in) |
| • | 5.79 mm (0.228 in) |
| • | 5.84 mm (0.230 in) |
| • | 5.89 mm (0.232 in) |
| • | 5.94 mm (0.234 in) |
| • | 5.99 mm (0.236 in) |
| • | 6.05 mm (0.238 in) |
| • | 6.10 mm (0.240 in) |
| • | 6.15 mm (0.242 in) |
| • | 6.20 mm (0.244 in) |
| • | 6.25 mm (0.246 in) |
| • | 6.30 mm (0.248 in) |
| • | 6.35 mm (0.250 in) |
| • | 6.40 mm (0.252 in) |
| • | 6.45 mm (0.254 in) |
| • | 6.50 mm (0.256 in) |
| • | 6.55 mm (0.258 in) |
Differential Carrier Bearing Preload Adjustment 8.0, 8.6 Inch Axle
Tools Required
| • | J 22779 Side Bearing Backlash Gage |
| • | J 25588 Side Bearing Shim Installer |
Important:
• The differential side bearing preload adjustment must be completed before the backlash adjustment can be started. • In order to maintain the original backlash, adjust the differential case side bearing preload by changing the thickness of the left and the right side shim packs equally. • Measure the service shims and the spacers one at a time. Add the measurements together in order to obtain the total thickness of the left or the right side shim pack. • Do not use or reuse the original cast iron production shims. Use service shims and spacers instead.
- Install the drive pinion, if necessary. Refer to Drive Pinion and Ring Gear Replacement.
- Measure the rotating torque of the drive pinion using an inch-pound torque wrench.
- Record the measurement.
- Install the differential assembly with the side bearings and bearing cups into the axle housing.
- Insert one 4.318 mm (0.170 in) thick service spacer into the left side of the axle housing.
- Side the differential assembly towards the service spacer in order to hold the spacer in place.
- Install the J 22779 between the right side differential side bearing cup and the axle housing.
- Tighten the knob on the J 22779 until there is moderate drag when the J 22779 is moved.
- Remove the J 22779 .
- Remove the service spacer.
- Using a micrometer, measure the thickness of the J 22779 in 3 locations.
- Calculate the average of the 3 measurements.
- Using a micrometer, measure the thickness of the service spacer.
- Add the thickness of the service spacer to the average thickness of the J 22779 .
- Insert one 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the axle housing.
- Insert one BENT 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the service shim.
- Install the J 22779 on the left side of the differential assembly.
- While rotating the ring gear back and forth, tighten the knob on the J 22779 until there is approximately 0.025-0.051 mm (0.001-0.002 in) of backlash between the ring gear and the drive pinion.
- Once the amount of backlash is obtained, remove the J 22779 .
- Remove the differential case with the differential side bearings and the bearing cups.
- Remove the service shims.
- Using a micrometer, measure the thickness of the J 22779 in 3 locations.
- Calculate the average of the 3 measurements.
- Subtract the service shim thickness for the left side of the axle, calculated in step 23, from the total service shim thickness, calculated in step 14.
- In order to initially set the preload of the differential side bearings and the backlash to approximately 0.013-0.023 mm (0.005-0.009 in), take the value determined in step 24 and add 0.0203 mm (0.008 in) service shim thickness to this amount.
- Assemble the left side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of selective service shims equaling the thickness determined in step 23.
- Assemble the right side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of selective service shims equaling the thickness determined in step 25.
- Install the differential assembly with the differential side bearings and the differential side bearing cups.
- Install the left side service spacer between the axle housing and the differential assembly.
- Install the left side selective service shim or shims.
- Install the right side service spacer between the axle housing and the differential assembly.
- Install the right side selective service shim or shims using the J 25588 , if necessary.
- Install the differential bearing caps and the bolts.
- Measure the drive pinion and differential side bearing preload using an inch-pound torque wrench.
- Record the measurement.
- Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in step 2, from the drive pinion and differential case bearing preload, measured in step 33.
- If the differential side bearing preload is not within specifications, add or subtract shim thickness equally from each shim pack as necessary in order to increase/decrease the side bearing preload.
- Once the differential side bearing preload is correct, measure the backlash and adjust, if necessary. Refer to Backlash Adjustment.
- Once the differential side bearing preload and backlash is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection.
Specification
The rotating torque of the drive pinion should be 1.7-3.4 N·m (15-30 lb in) for new bearings or 1.1-2.3 N·m(10-20 lb in) for used bearings.
Important: Before installation of the differential assembly, ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.
Important: Over-tightening may spread the housing and result in incorrect shim selection.
Record the measurement.
Record the measurement.
The resulting value is the total service shim thickness without preload for the axle.
This value is the left side service shim thickness without preload.
This value is the service shim thickness for the right side of the axle without preload.
Measure the service spacer and the service shims separately.
Add the measurements together in order to determine the total shim pack thickness.
Measure the service spacer and the service shims separately.
Add the measurements together in order to determine the total shim pack thickness.
The service shim or shims must be installed between the service spacer and the differential side bearing cup.
The service shim or shims must be installed between the service spacer and the differential side bearing cup.
Notice: Refer to Fastener Notice in the Preface section.
Tighten
Tighten the differential bearing cap bolts to 75 N·m (55 lb ft).
Rotate the pinion several times to ensure the differential side bearings have seated.
Specification
The rotating torque of the drive pinion and differential side bearings should be 3.9-6.2 N·m (30-55 lb in) for new bearings or 2.8-5.1 N·m (25-45 lb in)
for used bearings.
Multiply the value obtained by the axle ratio.
Specification
The differential case side bearing preload should be 1.7-4.0 N·m (15-35 lb in).
