Part 1
DISASSEMBLYPRE-INSPECTION
Before disassembling final drive, perform the following inspection.
- Total preload
a. Turn drive pinion in both directions several times to set bearing rollers.
b. Check total preload with Tool.
Tool number: ST3127SO00 (J25765-A)
Total preload: 1.4 - 1.7 Nm (14 - 17 kg-cm, 12 - 15 inch lbs.)
- Ring gear to drive pinion backlash
Check backlash of ring gear with a dial indicator at several points.
Ring gear-to-drive pinion backlash: 0.10 - 0.15 mm (0.0039 - 0.0059 inch)
- Ring gear runout
Check runout of ring gear with a dial indicator.
Runout limit: 0.05 mm (0.0020 inch)
- Tooth contact
Check tooth contact.
- Side gear to pinion mate gear backlash Using a feeler gauge, measure clearance between side gear thrust washer and differential case.
Clearance between side gear thrust washer and differential case: Less than 0.15 mm (0.0059 inch)
FINAL DRIVE HOUSING
1. Using three spacers [20 mm (0.79 inch)], mount final drive assembly on Tool.
Tool number: KV38100800 (J34310, J25604-01)
2. Remove differential side shaft assembly.
3. Remove differential side flange.
4. Put match marks on one side of side bearing cap with paint or punch to ensure that it is replaced in proper position during reassembly.
Bearing caps are line-bored during manufacture and should be put back in their original places.
5. Remove side bearing caps.
6. Remove differential case assembly with a pry bar.
Be careful to keep the side bearing outer races together with their respective inner cones - do not mix them up.
CAUTION: Side bearing spacer is placed on either the left or right depending upon final drive gear ratio. It should be labeled so that it may be replaced correctly.
7. Loosen drive pinion nut.
Tool number: ST38060002 (J34311)
8. Remove companion flange with puller.
9. Take out drive pinion together with rear bearing inner cone, drive pinion bearing spacer and pinion bearing adjusting washer.
10. Remove front oil seal and pinion front bearing inner cone.
11. Remove pinion bearing outer races with a brass drift.
12. Remove pinion rear bearing inner cone and drive pinion height adjusting washer.
Tool number: ST30031000 (J22912-01)
DIFFERENTIAL CASE
1. Remove side bearing inner cones.
To prevent damage to bearing, engage puller jaws in grooves.
Tool number:
A ST33051 001 (J22888-20)
B ST33061000 (J8107-2)
Be careful not to confuse the right and left hand parts. Keep bearing and bearing race for each side together.
2. Loosen ring gear bolts in a criss-cross pattern.
3. Tap ring gear off the differential case with a soft hammer.
Tap evenly all around to keep ring gear from binding.
4. Punch off pinion mate shaft lock pin from ring gear side.
DIFFERENTIAL SIDE SHAFT
1. Cut collar with cold chisel. Be careful not to damage differential side shaft.
2. Reinstall differential side shaft into extension tube and secure with bolts. Remove rear axle bearing by drawing out differential side shaft from rear axle bearing with puller.
3. Remove grease seal and oil seal.
INSPECTION
RING GEAR AND DRIVE PINION
Check gear teeth for scoring, cracking or chipping. It any damaged part is evident, replace ring gear and drive pinion as a set (hypoid gear set).
DIFFERENTIAL CASE ASSEMBLY
Check mating surfaces of differential case, side gears, pinion mate gears, pinion mate shaft and thrust washers.
BEARING
1. Thoroughly clean bearing.
2. Check bearing for wear, scratches, pitting or flaking. Check tapered roller bearing for smooth rotation. If damaged, replace outer race and inner cone as a set.
ADJUSTMENT
For quiet and reliable final drive operation, the following five adjustments must be made correctly:
1. Side bearing preload
2. Pinion gear height
3. Pinion bearing preload
4. Ring gear-to-pinion backlash. Refer to image.
5. Ring and pinion gear tooth contact pattern
SIDE BEARING PRELOAD
A selection of carrier side bearing adjusting washer is required for successful completion of this procedure.
1. Make sure all parts are clean and that the bearings are well lubricated with light oil or "DEXRON" type automatic transmission fluid.
2. Place the differential carrier, with side bearings and bearing races installed, into the final drive housing.
3. Put the side bearing spacer in place.
CAUTION: Side bearing spacer is placed on either the right or left depending upon final drive gear ratio. Be sure to replace it on the correct side.
4. Using Tool, install original carrier side bearing preload shims on the carrier end, opposite the ring gear.
Tool number: KV38100600 (J25267)
5. Install the side bearing caps in their correct locations and torque the bearing cap retaining bolts.
Specification: 88 - 98 Nm (9 - 10 kg.m, 65 - 72 ft. lbs.)
6. Turn the carrier several times to seat the bearings.
7. Measure the turning torque of the carrier at the ring gear retaining bolts with a spring gauge, J8129.
Specification: 34.3 - 39.2 Nm (3.5 - 4.0 kg, 7.7 - 8.8 lbs.) of pulling force at the ring gear bolt
8. If the carrier turning torque is not within the specification range, increase or decrease the total thickness of the side bearing adjusting washers until the turning torque is correct. If the turning torque is less than the specified range, install washers of greater thickness; if the turning torque is greater than the specification, install thinner washers. See the SDS section for washer dimensions and part numbers.
9. Record the total amount of washer thickness required for the correct carrier side bearing preload.
10. Remove the carrier from the final drive housing, saving the selected preload washers for later use during the assembly of the final drive unit.
PINION GEAR HEIGHT AND PINION BEARING PRELOAD
1. Make sure all parts are clean and that the bearings are well lubricated.
2. Assemble the pinion gear bearings into the pinion pre-load shim selector Tool, J34309.
- Front Pinion Bearing - make sure the J34309-3 front pinion bearing seat is secured tightly against the J34309-2 gauge anvil. Then turn the front pinion bearing pilot, J34309-5, to secure the bearing in its proper position.
- Rear Pinion Bearing - the rear pinion bearing pilot, J3430915, is used to center the rear pinion bearing only. The rear pinion bearing locking seat, J34309-4, is used to lock the bearing to the assembly.
3. Place the pinion preload shim selector Tool, J34309-1, gauge screw assembly with the pinion rear bearing inner cone installed into the final drive housing.
4. Assemble the front pinion bearing inner cone and the J34309-2 gauge anvil together with the J34309-1 gauge screw in the final drive housing. Make sure that the pinion height gauge plate, J34309-16, will turn a full 360 degrees, and tighten the two sections together by hand.
5. Turn the assembly several times to seat the bearings.
6. Measure the turning torque at the end of the J34309-2 gauge anvil using torque wrench J25765A.
Turning torque specification: 1.0 - 1.3 Nm (10 - 13 kg.cm, 8.7 - 11.3 inch lbs.)
7. Place the J34309-1 "R200A" pinion height adapter onto the gauge plate and tighten it by hand.
CAUTION: Make sure all machined surfaces are clean.
PINION BEARING PRELOAD WASHER SELECTION
8. Place the solid pinion bearing spacer, small end first, over the J34309-2 gauge anvil and seat the small end squarely against the tip of the J34309-1 gauge screw in the tool recessed portion.
9. Select the correct thickness of pinion bearing preload adjusting washer using a standard gauge of 3.5 mm (0.138 inch) and your J34309-101 feeler gauge. The exact measure you get with your gauges is the thickness of the adjusting washer required. Select the correct washer.
Drive pinion bearing preload adjusting washer: Refer to image.
10. Set your selected, correct pinion bearing preload adjusting washer aside for use when assembling the pinion gear and bearings into the final drive.