Rear Differential Service Part 1
DISASSEMBLED VIEW
INSPECTING THE AXLE BEFORE DISASSEMBLY
1. Remove the axle cover from the rear axle and drain the axle lubricant into a suitable container.
2. Check ring gear backlash. Refer to "BACKLASH ADJUSTMENT". This information can be used to determine the cause of the axle problem. It will also help when setting up the shim packs for locating and preloading the differential cage.
3. Check case for metal chips and shavings. Determine where these ships and shavings come from, such as a broken gear or bearing cage.
- If possible, determine the cause of the axle problem before disassembly.
DISASSEMBLY
1. Remove axle shafts.
2. Remove ABS sensor.
3. Remove bearing caps and bolts.
- Mark the caps and the housing as left and right.
CAUTION: Bearing caps are machined with the housing and must be assembled in the same position as removed. Note the matched letter stamped on the caps and carrier. When assembled, the letters on the caps must agree in both the horizontal and vertical position with the letters on the carrier.
4. Remove Differential case.
- Pry the case from the axle housing at the differential "window".
5. Remove side bearing outer races and shims.
- Mark the races and shims as left and right, and place them with the bearing cups.
6. Remove differential side bearings using remover J-42379 and plug J-39830.
- Select insert; 303174 and collet halves ; 44801 in remover kit J-42379.
7. Remove ring gear bolts.
- Ring gear bolts use right handed threads.
CAUTION: DO not pry the ring gear from the case. This will damage the ring and the differential case.
8. Remove ring gear from the differential.
- Drive the ring gear off with a brass drift if necessary.
- Check drive pinion bearing preload.
- Check the pinion assembly for looseness by moving it back and forth. (Looseness indicates excessive bearing wear.)
9. Remove pinion flange nut and washer.
- Use flange holder J-8614-01 to hold the pinion flange.
10. Remove pinion flange.
- Use flange holder J-8614-01 to remove the pinion flange.
11. Remove pinion from the axle housing.
- Thread the pinion nut halfway onto the pinion.
- Drive the pinion out of the housing with a hammer and a soft drift.
- Remove the nut and then remove the pinion.
12. Remove collapsible spacer (1).
13. Remove outer seal, outer oil slinger and outer pinion bearing.
14. Remove inner bearing, inner oil slinger and shim from the pinion.
- Press the bearing off the pinion using remover J-42379.
- Select insert; 303174 and collet halves ; 44801 in remover kit J-42379.
- Remove the shim.
15. Remove bearing cups and baffle plate from the axle housing using a hammer and a punch.
- Work the cups out of the housing evenly, moving the punch back and forth between one side of the cup and the other.
- The baffle plate will be destroyed and should be replaced with a new one.
16. Remove exciter ring.
- Remove the exciter ring from the differential using a mallet or a brass hammer if it is required.
NOTE: Discard the exciter ring after removal.
CLEANING
Do not steam clean drive parts which have ground and polished surfaces such as gears, bearings, and shafts. These parts should be cleaned in a suitable solvent. All parts should be disassembled before cleaning.
Parts should be thoroughly dried immediately after cleaning. Use soft, clean, lintless rags. Parts may be dried with compressed air. Do not allow the bearings to spin while drying them with compressed air.
INSPECTION AND REPAIR
It is very important to carefully and thoroughly inspect all drive unit parts before reassembly.
Thorough inspection of the drive parts for wear or stress and subsequent replacement of worn parts will eliminate costly drive component repair after reassembly.
Axle Housing
- The carrier bore for nicks or burrs that would prevent the outer diameter of the pinion seal from sealing, Remove any burrs that are found.
- The bearing cap bores for nicks or burrs. Remove any burrs that are found.
- The housing for cracks. Replace the housing if any cracks are found.
- The housing for foreign material such as metal chips, dirt, or rust.
Pinion And Ring Gear
- Pinion and ring gear teeth for cracking, chipping, scoring, or excessive wear.
- Pinion splines for wear.
- Pinion flange splines for wear.
- The sealing surface of the pinion flange for nicks, burrs, or rough tool marks which would cause damage to the seal's inside diameter and result in an oil leak.
- Replace all worn or broken parts.
- Ring and pinion gears are matched sets and are both replaced anytime a replacement of either is necessary.
Bearings
- Bearings visually and by feel.
- The bearings should feel smooth when oiled and rotated while applying as much hand pressure as possible. The large end of the bearing rollers for wear. This is where tapered roller bearing wear is most evident.
- Bearing cups for wear, cracks, brinelling and scoring.
- Bearing and cups are only replaced as sets.
- If the rear axle was operated for an extended period of time with very loose bearings, the ring gear and drive pinion will also require replacement.
- Low mileage bearings may have minute scratches and pits on the rollers and the bearing cups from the initial pre-load. Do not replace a bearing for this reason.
- Bearing cups for cracks or chips.
Shims
Shims for cracks and chips. Damaged shims should be replaced with an equally sized service shim.