Differential Overhaul

PRESET TORQUE
Inspection
On-Vehicle:
1. Block the front wheels.
2. Shift to low gear.
3. Lift up rear wheels, and place the safety stand.





4. Measure preset torque clockwise using a torque wrench as shown.

Standard: 118 - 275 Nm (112 - 28 kg/m; 87 - 203 ft. lbs.)
Service Limit: 60 Nm (6 kg/m; 43 ft. lbs.)

5. If preset torque is less than the service limit, replace the limited slip differential clutch set. Adjust the 65 mm (differential housing cover side) and 112 mm (differential housing cover side) shims whenever the clutch set is replaced.

Assembly:





1. Place one special tool in a vise. Place the left side of the differential assembly on the special tool, then preset the differential with 3 - 5 rotations, counterclockwise.





2. Measure preset torque counterclockwise using a torque wrench as shown.

Standard: 59 - 137 Nm (6 - 14 kgf-m, 43 - 101 ft. lbs.)
Service Limit: 30 Nm (3 kg/m; 22 ft. lbs.)

3. If preset torque is less than the service limit, replace the limited slip differential clutch set. Adjust the 65 mm and 112 mm shims whenever the clutch set is replaced.

BEARING
Replacement

NOTE:
- The bearing and outer race should be replaced as a set.
- Inspect and adjust the bearing preload whenever the bearing is replaced.





1. Remove the tapered roller bearings using the bearing pullers.





2. Install the tapered roller bearings using a special tool and a press. Press the tapered roller bearings squarely until they bottom against the case.

DIFFERENTIAL
Disassembly





1. Hold the differential in a bench vise using a special tool, then remove the differential housing mounting bolts in a crisscross pattern in several steps.





2. Remove the differential housing, stop plate, washer, thrust needle bearing, and 65 mm shim.





3. Remove the 112 mm shim, clutch discs, clutch plates, and 102 mm washer.





4. Remove the parts shown below.





5. Screw two 8 x 1.0 mm bolts into the threaded holes in the differential housing cover to push it away from the final driven gear. Turn each bolt two turns at a time to prevent cocking the differential housing cover excessively.

Reassembly

NOTE:
- If the limited slip differential clutch set was replaced, the 65 mm shim (differential housing cover side) and 112 mm shim (differential housing cover side) must be adjusted.
- Reassemble the parts in the same order and direction they were before disassembly.
- Lubricate the clutch disc surface with transmission oil.





1. Reassemble the parts as shown below. Position the 65 mm shim with the thickness stamp mark facing up.





2. Install the carrier assembly.





3. Install the final driven gear. Align the mark on the differential housing cover with the mark on the final driven gear.





4. Install the washers, thrust needle bearing, and central gear.
5. Clean the gear end surface on the central gear.





6. Set the plastigage (Blue) strip on the central gear at four points in a crisscross pattern.





7. Install the washer, thrust needle bearing, 65 mm shim, 112 mm shim, clutch disc, and spring plate. Be careful not to move the plastigage when installing the washer. Position the 65 mm shim with the thickness stamp mark facing up.





8. Align the marks, then install the differential housing cover.





9. Tighten the mounting bolts in a crisscross pattern in several steps.





10. Remove the parts shown below.





11. Measure the widest part of the plastigage.

Standard: 0.18-0.229 mm

- If the plastigage measures within the standard, go to step 14.
- If the plastigage does not measure within the standard, continue with step 12.





12. Select the proper 65 mm shim based on the following table.
- If the measurement was less than 0.18 mm, in stall a thinner shim.
- If the measurement was more than 0.229 mm, install a thicker shim.
13. After installing a thinner or thicker shim, be sure to recheck the measurement with plastigage.
- After installing a thinner shim:
If the measured value is less than 0.18 mm, select the next thinner shim, and recheck. If the new value is more than 0.229 mm, the selected shim is OK.
- After installing a thicker shim:
If the measured value is more than 0.229 mm, select the next thicker shim, and recheck. If the new value is less than 0.18 mm, take the shim you chose at the step 12.





14. Install the washer, thrust needle bearing, 65 mm shim, 112 mm shim, clutch plate, clutch disc, and spring plate. Position the 65 mm shim with the thickness stamp mark facing up.





15. Align the marks, then install the differential housing cover.





16. Tighten the mounting bolts in a crisscross pattern in several steps.





17. Measure the preset torque.

Standard: 59 - 137 Nm (6 - 14 kgf-m, 43 - 101 ft. lbs.)

- If the preset torque is more than the standard, select a thinner 112 mm shim, and recheck the preset torque.
- If the preset torque is less than the standard, select a thicker 112 mm shim, and recheck the preset torque.

OIL SEAL
Removal
1. Remove the differential assembly.





2. Remove the oil seal from the transmission housing.





3. Remove the oil seal from the clutch housing.

BEARING OUTER RACE
Replacement (Clutch Housing Side)

NOTE:
- The outer race and bearing should be replaced as a set.
- Inspect and adjust the bearing preload whenever the bearing is replaced.





1. Remove the bearing outer race, 90 mm washer, and oil guide ring using the special tools.





2. Install the oil guide ring and 90 mm washer, then drive the outer race into the clutch housing using the special tools.

BEARING PRELOAD
Adjustment
If any of the items listed below are replaced, the bearing preload must be adjusted.
- TRANSMISSION HOUSING
- CLUTCH HOUSING
- DIFFERENTIAL
- TAPERED ROLLER BEARING and OUTER RACE
- 75 mm THRUST SHIM
- 90 mm WASHER
- OIL GUIDE RING





1. Remove the bearing outer race and 75 mm thrust shim from the transmission housing by prying up on the bearing outer race or by heating the housing to about 212°F (100°C).

CAUTION: Do not reuse the thrust shim if the outer race was pried out.

NOTE:
- If the outer race was removed by heating the case, let the transmission cool to room temperature before adjusting the bearing preload.
- Do not heat the transmission housing in excess of 212°F (100°C).
- Replace the bearing with a new one whenever the outer race is replaced.
- Repeat on the clutch side.





2. Install the standard shim and bearing outer race into the transmission housing using the special tools. Install the bearing outer race squarely, and check that there is no clearance between the bearing outer race, shim and transmission housing.

CAUTION: Do not use more than one shim to adjust the bearing preload.

3. Lubricate the tapered roller bearing with transmission oil, then install the differential.
4. Install the transmission housing. Do not install the mainshaft, countershaft, and reverse idle gear shaft.

Torque: 44 Nm (4.5 kg/m; 33 ft. lbs.)

5. Rotate the differential assembly in both directions to seat the bearings.





6. Measure the starting torque of the differential assembly with a special tool and a torque wrench. Measure the bearing preload at normal room temperature in both directions.

Standard: 2.0 - 3.0 Nm (20 - 30 kg/cm; 17 - 26 inch lbs.)

7. If the bearing preload is not within the standard, select the shim that will give you the correct preload, and recheck.
Changing one of the shims to the next size will increase or decrease preload about 0.3 - 0.4 Nm (3 - 4 kg/cm; 2.60 - 3.47 inch lbs.).

OIL SEAL
Installation





1. Install the oil seal into the transmission housing using the special tools.





2. Install the oil seal into the clutch housing using the special tools.