Part 1
PRE-INSPECTION
Before disassembling final drive, perform the following inspection.
- Total preload
a. Turn drive pinion in both directions several times to seat bearing rollers correctly.
b. Check total preload with Tool.
Tool number: ST3127SO00 (J25765-A)
Total preload: 1.7 - 2.5 Nm (17 - 25 kg.cm, 15 - 22 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: 0.13 - 0.18 mm (0.0051 - 0.0071 inch)
- Ring gear runout Check runout of ring gear with a dial indicator.
Runout limit: 0.08 mm (0.0031 inch)
- Tooth contact
Check tooth contact.
- Side gear to pinion mate gear backlash
Measure clearance between side gear thrust washer and differential case with a feeler gauge.
Clearance between side gear thrust washer and differential case: 0.10 - 0.20 mm (0.0039 - 0.0079 inch)
DIFFERENTIAL CARRIER
1. Mount final drive assembly on Tool.
Tool number: ST06340000 (J24310,J34310)
2. 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.
3. Remove side lock fingers and side bearing caps.
4. Remove side bearing adjuster with Tool.
Tool number: ST32580000 (J34312)
5. 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.
6. Remove drive pinion nut with Tool.
Tool number: KV38104700 (J34311)
7. Remove companion flange with puller.
8. Take out drive pinion together with pinion rear bearing inner cone, drive pinion bearing spacer and pinion bearing adjusting shim.
9. Remove front oil seal and pinion front bearing inner cone.
10. Remove pinion bearing outer races with a brass drift.
11. Remove pinion rear bearing inner cone and drive pinion adjusting washer.
Tool number: ST30031000 (J22912-01)
DIFFERENTIAL CASE
1. Remove side bearing inner cones.
To prevent damage to bearing, engage puller jaws in groove.
Tool number:
A ST33051001 (J22888-20)
B ST33061000 (J8107-2)
Be careful not to confuse the left and right 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 differential case with a soft hammer.
Tap evenly all around to keep ring gear from binding.
4. Drive out pinion mate shaft lock pin, with punch from ring gear side.
Lock pin is caulked at pin hole mouth on differential case.
INSPECTION
RING GEAR AND DRIVE PINION
Check gear teeth for scoring, cracking or chipping. If 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 bearings for wear, scratches, pitting or flaking.
Check tapered roller bearing for smooth rotation. If damaged, replace outer race and inner cone as a set.
LIMITED SLIP DIFFERENTIAL
PREPARATION FOR DISASSEMBLY
Checking Differential Torque
Measure differential torque with Tool.
If it is not within the specifications, inspect components of limited slip differential.
Differential torque: 88 - 108 Nm (9 - 11 kg.m, 65 - 80 ft. lbs.)
Tool number: A KV38105210
Tool number: B KV38105220
DISASSEMBLY
CAUTION: Do not run engine when one wheel (rear) is off the ground.
1. Remove side bearing inner cone with Tool.
2. Loosen ring gear bolts in a criss-cross pattern.
3. Tap ring gear off gear case with a soft hammer.
Tap evenly all around to keep ring gear from binding.
4. Remove couple bolts on differential cases A and B with a press.
Tool number: ST33081000
5. Separate differential case A and B.
Draw out component parts (discs and plates, etc.).
Put marks on gears and pressure rings so that they can be reinstalled in their original positions from which they were removed.
INSPECTION
Contact Surfaces
1. Clean the disassembled parts in suitable solvent and blow dry with compressed air.
2. If following surfaces are found with burrs or scratches, smooth with oil stone.
1 Differential case B
2 Differential case A
3 Side gear
4 Pinion mate gear
5 Pinion mate shaft
6 Friction plate guide
Disc and Plate
1. Clean the discs and plates in suitable solvent and blow dry with compressed air.
2. Inspect discs and plates for wear, nicks and burrs.
3. To test it friction disc or plate is not distorted, place it on a surface plate and rotate it by hand with indicating finger of dial gauge resting against disc or plate surface.
Allowable warpage: 0.08 mm (0.0031 inch)
If it exceeds limits, replace with a new plate to eliminate possibility of clutch slippage or sticking.
4. Measure frictional surfaces and projected portions of friction disc, friction plate, spring plate, and determine each part's differences to see if the specified wear limit has been exceeded.
If any part has worn beyond the wear limit, and deformed or fatigued, replace it with a new one that is the same thickness as the projected portion.
Wear limit: 0.1 mm (0.004 inch) or less
A - B = Wear limit mm (inch)
^: Measuring points
A: Projected portion
B: Frictional surface
ADJUSTMENT
Friction Disc and Friction Plate End Play
End play of friction disc and friction plate can be calculated by using following equation and should be adjusted within following range. Adjustment can be made by selecting friction disc having two different thicknesses.
End play E: 0.05 - 0.15 mm (0.0020 - 0.0059 inch)
E = A - (B + C)
A: Length of differential case contact surface to differential case inner bottom.
B: Total thickness of friction discs, friction plates, spring disc and spring plate in differential case on one side.
C: Length of differential case contact surface to back side of side gear.
1. Measure values of "A".
Standard length A: 49.50 - 49.55 mm (1.9488 - 1.9508 inch)
2. Measure thickness of each disc and plate.
Total thickness "B": 19.24 - 20.26 mm (0.7575 - 0.7976 inch)
3. Measure values of "C".
a. Attach a dial indicator to the base plate.
b. Place differential case B on the base plate, and install a master gauge on case B.
Then adjust the dial indicator scale to zero with its tip on the master gauge.
c. Install pinion mate gears, side gears and pinion mate shaft in differential case B.
d. Set dial indicator's tip on the side gear, and read the indication.
Example:
E = A - D = A - (B + C) = 0.05 to 0.15 mm
A = 49.52 mm
B = 19.45 mm
C = 29.7 mm
D = B + C
49.15 (D) = 19.45 (B) + 29.7 (C)
E = A - D
0.37 (E) = 49.52 (A) - 49.15 (D)
From the above equation, end play of 0.37 mm exceeds the specified range of 0.05 to 0.15 mm. Select suitable discs and plates to adjust correctly.
ASSEMBLY
Prior to assembling discs and plates, properly lubricate the M by dipping them in limited slip differential oil.
1. Alternately position specified number of friction plates and friction discs on rear of side gear.
Always position a friction plate first on rear of side gear.
2. Install spring plate.
3. Install friction plate guides.
Correctly align the raised portions of friction plates, and apply grease to inner surfaces of friction plate guides to prevent them from failing.
4. Install differential case B over side gear, discs, plates and friction plate guide assembly.
- Install differential case B while supporting friction plate guides with your middle finger inserted through oil hole in differential case.
- Be careful not to detach spring disc from the hexagonal part of the side gear.
5. Install pinion mate gears and pinion mate thrust washers on pinion mate shaft, then install pinion mate shaft in differential case B.
6. Install side gear to pinion mate gears.
7. Install each disc and plate.
Use same procedures as outlined in steps 1. through 4. above.
8. Install differential case A.
Position differential cases A and B by correctly aligning marks stamped on cases.
9. Tighten differential case couple bolts.
10. Place ring gear on differential case and tighten ring gear bolts.
Tighten bolts in a criss-cross pattern, lightly tapping bolt head with a hammer. Then bend up lock straps to lock the bolts in place.
11. Install side bearing inner cone.
12. Check differential torque.