Rear Drive Axle Disassembly
^ Tools Required^ J 2619-01 Slide Hammer
^ J 8107-4 Side Bearing Puller Pilot
^ J 8614-01 Companion Flange Holder
^ J 22813-01 Axle Bearing Puller
^ J 22888-20A Side Bearing Puller
^ J 22912-01 Bearing Remover
1. Raise and support the vehicle.
2. Support the axle using a suitable portable safety stand.
3. Remove the tires and wheels.
4. Remove both brake drums.
5. Remove the axle cover bolts, the cover and the gasket. Drain the axle lubricant.
6. Remove the pinion shaft lock bolt.
7. Remove the pinion shaft.
^ Push the axle shaft in towards the center of the differential case.
^ Remove the C lock from the end of the axle shaft.
8. Remove the axle shaft from the axle housing.
9. Remove the oil seal using a seal removal tool. Do not damage the housing.
Important: The jaws of the tool must engage the bearing outer race.
10. Remove the bearing, using the J 2619-01 and the J 22813-01.
11. Remove the differential pinion and the side gears.
12. Roll the pinion gears out of the case with the pinion thrust washers.
13. Mark the gears and the differential case LEFT and RIGHT when removing the side gears and the side gear thrust washers.
14. Remove the bearing caps and bolts. Mark the caps and the housing LEFT and RIGHT.
Notice: When removing the differential case from the axle housing, do not damage the cover gasket surface. If the cover gasket surface is damaged, lubricant may leak from the axle and cause premature failure of the axle assembly.
15. Remove the differential case.
16. Pry the case from the axle housing at the differential window.
17. Remove the bearing outer races, the shims, and the spacers.
18. Mark the races and shims LEFT and RIGHT. Place the races and the shims with the bearing caps.
Important: The jaws of the J 22888-20A must pull from beneath the bearing cone and not the cage.
19. Remove the differential side bearings, using the J 8107-4 and the J 22888-20A.
20. Remove the left handed threaded ring gear bolts.
Notice: Do not pry the ring gear from the case. This will damage the ring gear and differential case.
21. Remove the ring gear from the differential. Drive the gear off using a brass drift if necessary.
22. Inspect the differential drive pinion bearing preload.
^ If there is no reading, inspect the drive pinion gear for looseness by shaking the gear.
^ When operating the rear axle for an extended period of time with loose bearings or a worn yoke, you will need to replace the ring and pinion gear.
Important: Note the pinion preload torque for reassembly.
23. Inspect the pinion assembly for looseness by moving the pinion back and forth. Looseness indicates excessive bearing wear.
24. Remove the pinion flange nut and washer using the J 8614-01 in order to hold the pinion flange.
25. Remove the pinion flange using the J 8614-01.
26. Remove the pinion from the axle housing.
^ Thread the pinion nut halfway onto the pinion.
^ Install the differential cover with two bolts in order to prevent the pinion from falling.
^ Drive the pinion out of the housing using a hammer and a drift.
^ Remove the pinion and cover.
27. Remove the collapsible spacer from the pinion. Discard the spacer.
28. Remove the inner bearing and the shim from the pinion.
29. Press the bearing off of the pinion using the J 22912-01.
30. Remove the shim.
31. Remove the outer seal, using a seal removal tool, and the outer pinion bearing.
32. Remove the drive pinion bearing cups from the axle housing using a hammer and punch in the slots provided. Move the punch back and forth between one side of the cup and the other in order to work the cups out of the housing evenly.
33. Inspect the bearings.
34. Inspect the shims.
35. Inspect the ring and pinion gear.
36. Inspect the rear axle housing.
Rear Axle Housing Inspection
Carefully and thoroughly inspect all drive unit parts before assembly. Thorough inspection of the drive parts for wear or stress with subsequent replacement of worn parts eliminates costly drive component repair after assembly.
^ Inspect for nicks or burrs that could prevent the outer diameter of the pinion seal from sealing. Remove any burrs.
^ Inspect the bearing cup bores for nicks or burrs. Remove any burrs that are found.
^ Inspect the housing for cracks. Replace the housing if any cracks are found.
^ Inspect the housing for foreign material such as metal chips, dirt, or rust.
Bearings Inspection
Carefully and thoroughly inspect all drive unit parts before assembly. Thorough inspection of the drive parts for wear or stress with subsequent replacement of worn parts eliminates costly drive component repair after assembly.
Important: Bearings and cups are matched sets. Replace both bearing and cup when either part requires replacement
^ Oil the bearings. Inspect the bearings for smooth rotation.
^ Inspect the bearing rollers for wear.
^ Inspect the bearing cups for wear, cracks, brinelling, and scoring.
Shims Inspection
Carefully and thoroughly inspect all drive unit parts before assembly. Thorough inspection of the drive parts for wear or stress with subsequent replacement of worn parts eliminates costly drive component repair after assembly.
Inspect shims for cracks and chips. Replace damaged shims with a service shim of an equal size.
Differential Case Assembly
^ Tools Required
- J 8092 Driver Handle
- J 8107-4 Differential Side Bearing Puller Pilot
- J 25299 Differential Side Bearing Installer
1. Lubricate all the parts using axle lubricant.
2. Install the thrust washers to the side gears.
3. Install the side gears to the differential case on the same side in which the parts were removed.
4. Place one pinion gear on the side gear. Rotate the gear until the pinion is exactly opposite the differential opening.
5. Install the differential thrust washers.
6. Rotate the pinion gears into place. Verify that the gears are aligned with the pinion shaft holes.
7. Install the pinion shaft.
8. Install the pinion shaft lock bolt finger tight.
9. Inspect the mating surfaces of the differential case for cleanliness and that the surfaces are free of burrs.
10. Install the ring gear to the differential case.
11. Install two threaded studs into the ring gear on opposite sides.
12. Place the ring gear on the case. Align the studs with the holes in the case.
13. Install the ring gear bolts. Tighten the ring gear bolts alternately and in stages, gradually pulling the ring gear onto the differential case.
^ Tighten the ring gear bolts in sequence to 120 Nm (90 ft. lbs.).
14. Install the differential side bearings, using the J 25299, the J 8092, and the J 8107-4.
^ In order to protect the differential case, place the J 8107-4 in the case on the side opposite the bearing installation.
^ Drive the bearing onto the case using the J 25299 and the J 8092.
15. Install the differential case to the axle housing. Refer to Differential Side Bearing Preload Adjustment.
Differential Side Bearing Preload Adjustment
^ Tools Required
- J 22779 Side Bearing Backlash Gauge
^ 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 shims equally.
^ Measure the production shims and the spacers one at a time. Add the measurements together in order to obtain the sizes of the right and the left shim packs. Production shims are cast iron. Do not reuse production shims.
- Service spacer thickness is nominal at 4.32 mm (0.170 inch).
- Service shims are available from 1.02 - 2.54 mm (0.040 - 0.100 inch) in increments of 0.101 mm (0.004 inch).
- The side bearing surfaces must be clean and free of burrs.
1. Place the case, with the bearing cups installed, into the axle housing.
1. Lubricate the axle bearings using axle lubricant.
2. Support the case in order to prevent the case from falling into the axle housing.
2. Insert the J 22779 between the axle housing and the left bearing cup.
3. Turn the adjusting nut to the right until you produce a noticeable drag, while moving the tool back and forth in the bore.
1. Tighten the lock bolt on the side of the tool.
2. Leave the tool in place.
4. Install a service spacer and a shim between the right bearing cup and the axle housing.
Insertion of progressively larger feeler gauge sizes between the axle housing and the service shim determines the bearing preload.
1. Push the feeler gauge downward so that the feeler gauge contacts the shim at the top and the bottom, and then contacts the axle housing.
2. The correct feeler gauge thickness is the point just before additional drag begins. This is the zero setting without the preload.
3. Remove the following components from the vehicle:
1. The strap
2. The J 22779
3. The service spacer
4. The service shim
5. The feeler gauge
6. The differential case from the axle housing
4. Measure the J 22779 gauge plate thickness in three places using a micrometer. Average the readings.
5. Add the readings of the right side service spacer, the service shim, and the feeler gauge.
6. For the initial backlash setting, move the ring gear from the pinion by subtracting 0.25 mm (0.010 inch) from the ring gear side shim pack and adding 0.25 mm (0.010 inch) to the shim pack on the opposite side.
7. In order to obtain the proper preload on the side bearings, add 0.10 mm (0.004 inch) to the measurement of each shim pack.
8. Install the differential and adjust the ring and pinion gear backlash. Refer to Backlash Adjustment.
Backlash Adjustment
1. Install the differential case, the bearing cups, the spacers, and the shims as determined from the side bearing preload adjustment. Refer to Differential Side Bearing Preload Adjustment.
2. Rotate the case several times in order to seat the bearings.
Using a magnetic base, install a dial indicator to the case.
3. Place the indicator stem at the heel end of a gear tooth.
4. Set the dial indicator so that the stem is aligned with the gear rotation and perpendicular to the tooth angle.
5. Install the differential bearing caps and the bolts.
^ Tighten the bolts to 75 Nm (55 ft. lbs.).
6. Inspect and record the backlash at three or four points around the ring gear.
^ When checking backlash, hold the pinion stationary.
^ The backlash should be the same at each point within 0.05 mm (0.002 inch). If the backlash varies more than 0.05 mm (0.002 inch), inspect for the following conditions:
- Burrs
- A distorted case flange
- Uneven bolting
7. For all new gear sets, backlash at the minimum lash point measured should be 0.13 - 0.23 mm (0.005 - 0.009 inch).
8. If the backlash is not within specifications, move the ring gear in or out from the pinion by increasing the thickness of one shim, and decreasing the thickness of the other shim an equal amount. This will maintain the correct axle side bearing preload.
Moving 0.05 mm (0.002 inch) of shim from one side of the differential to the other will change the backlash adjustment by 0.03 mm (0.001 inch).
9. When you have correctly adjusted the backlash, remove the bearing caps and the shim packs.
10. Select a shim 0.10 mm (0.004 inch) thicker than the one removed from the left side. Insert this shim between the spacer and the left bearing race.
11. Install the left bearing cap and bolts. Do not tighten.
12. Select a shim 0.10 mm (0.004 inch) thicker than the shim removed from the right side. Insert the shim between the spacer and the right bearing race. Drive the shim into place.
13. Install the right side bearing cap and bolts.
^ Tighten the bolts to 75 Nm (55 ft. lbs.).
14. Recheck the backlash. Correct as necessary.
15. Once 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 Check.
Gear Tooth Contact Pattern Check
Before the final assembly of the differential, perform a gear tooth contact pattern check.
A gear tooth contact pattern check is NOT a substitute for adjusting the pinion depth and the backlash. The gear tooth contact pattern check is a final check in order to verify the correct running position of the ring gear and the drive pinion. Any gear sets that are not aligned properly may be noisy and have a short life. With a pattern check, the best contact between the ring gear and the drive pinion for low noise level and long life can be ensured.
Gear Tooth Terms
^ The side of the ring gear tooth that curves outward, or is convex, is the DRIVE side (4).
^ The concave side is the COAST side (3).
^ The end of the tooth nearest center of the ring gear is the TOE end (2).
^ The end of the tooth farthest away from the center is the HEEL end (1).
^ The toe end of the tooth is smaller than the heel end.
Testing Procedure
Important: A test that is performed without loading the gears will not result in a satisfactory pattern.
1. Wipe the oil out of the carrier. Carefully clean each tooth of the ring gear.
2. Apply gear marking compound sparingly to all ring gear teeth using a medium stiff brush. When properly used, the area of pinion tooth contact will be visible when hand load is applied.
Important: Do not turn the ring gear excessively.
3. Using a torque wrench, apply a load until a torque of 13 Nm (9.6 ft. lbs.) is required in order to turn the pinion.
1. Turn the companion flange using a wrench so that the ring gear rotates 6 full revolutions.
2. Reverse the rotation so that the ring gear rotates 6 revolutions in the opposite direction.
3. Observe the pattern on the ring gear teeth.
Adjustments Affecting Tooth Contact
There are two adjustments, backlash and pinion depth, which will affect the tooth contact pattern. The effects of the bearing preloads are not easily seen on hand loaded teeth pattern tests. Perform the adjustments within specifications before proceeding with the backlash and the drive pinion adjustments.
Adjust the pinion depth and the backlash as necessary, in order to obtain the correct pattern.
The pinion depth is adjusted by increasing or decreasing the shim thickness between the pinion head and the inner race of the rear bearing. The shim is used in the differential in order to compensate for the manufacturing tolerances. Increasing the shim thickness will move the pinion closer to the centerline of the ring gear.
The backlash is adjusted by means of the side bearing adjusting sleeves which move the entire case and the ring gear assembly closer to, or farther from the drive pinion. The adjusting sleeves are also used in order to set the side bearing preload. In order to increase the backlash, turn the left sleeve in and turn the right sleeve out an identical amount. In order to decrease the backlash, turn the right sleeve in and turn the left sleeve out an identical amount.
The contact pattern must be centrally located up and down on the face of the ring gear teeth.