Differential Assembly: Service and Repair

M/T DIFFERENTIAL




Component Location Index

BACKLASH INSPECTION





1. Place the differential assembly on V-blocks (A), and install both axles.
2. Measure the backlash of both pinion gears (B) with a dial indicator (C). If the backlash is not within the standard, replace the differential carrier.

Standard (New): 0.05-0.15 mm (0.002-0.006 inch)

FINAL DRIVEN GEAR/CARRIER REPLACEMENT





1. Remove the bolts (left-hand threads) in a crisscross pattern in several steps, then remove the final driven gear from the differential carrier.
2. Install the final driven gear with the chamfer on the inside diameter facing the carrier. Tighten the bolts in a crisscross pattern in several steps.
3. Adjust the carrier bearing preload.

CARRIER BEARINGS REPLACEMENT

Special Tools Required
- Driver 40 mm I.D. 07746-0030100
- Bearing Attachment 07LAD-PW50601

1. Check the carrier bearings for wear and rough rotation. If they rotate smoothly and their rollers show no signs of wear, the bearings are OK.





2. Remove the carrier bearing (A) with a commercially-available bearing puller (B) and bearing separator (C).





3. Install the new bearings with the special tool and a press. Press each bearing on until it bottoms. There should be no clearance between the bearings and the carrier.
4. Inspect the bearing preload.

OIL SEAL REPLACEMENT

Special Tools Required
- Driver 07749-0010000
- Driver Attachment 07GAD-PG401 00
- Pilot 28 x 30 mm 07JAD-PH80400
- Driver Attachment 07JAD-PH801 01

1. Remove the differential assembly.





2. Remove the oil seal (A) from the transmission housing (B).





3. Remove the oil seal (A) from the clutch housing (B).





4. Install the new oil seal (A) in the transmission housing (B) with the special tools.





5. Install the new oil seal (A) in the clutch housing (B) with the special tools.

CARRIER BEARINGS PRELOAD ADJUSTMENT

Special Tools Required
- Driver 07749-0010000
- Attachment 52 x 55 mm 07746-0010400
- Attachment 62 x 68 mm 07746-0010500
- Attachment 72 x 75 mm 07746-0010600

If any of the items listed below were replaced, the carrier bearing preload must be adjusted.
- Transmission housing
- Clutch housing
- Differential carrier
- Carrier bearing and outer race

1. Remove the oil seals from the transmission housing and clutch housing.





Thrust Shim Replacement (Transmission Housing)
2. Drive the bearing outer race (A) and thrust shim (B) out of the transmission housing (C). Do not reuse the thrust shim. If you replaced the carrier bearing on the transmission housing side of the carrier, discard the outer race.





3. If you replaced the carrier bearing on the clutch housing side of the carrier, remove and discard the bearing outer race, Heat up the clutch housing to about 212°F (100°C) with a heat gun (A), then remove the outer race (B) and the 75 mm shim (C). Do not heat the housing in excess of 212°F (100°C).





4. Select a new thrust shim that's the same size as the one you removed, and use the special tools to install it (A) and the bearing outer race (B) in the transmission housing. (Use a new race if you replaced the bearing.) There should be no space between the race, shim, and housing.





5. If you removed the bearing outer race from the clutch housing, use the special tools to install a new one (A) along with the 75 mm shim (B). There should be no space between the race, shim, and housing.
6. With the mainshaft and countershaft removed, install the differential assembly, bolt the transmission and clutch housing together, and torque the 10 mm bolts to 47 Nm (4.8 kgf-m, 35 ft. lbs.) and the 8 mm bolts to 27 Nm (2.8 kgf-m, 20 ft. lbs.).
7. Rotate the differential assembly in both directions to seat the tapered roller bearings.





8. At normal room temperature, measure the starting torque of the differential assembly by rotating it in both directions with the special tool and a torque wrench (A).

STANDARD: 1.4 - 2.5 Nm (14 - 26 kgf-cm, 12 - 23 inch lbs.)

9. If the carrier bearing preload is not within the standard, select a thrust shim that will provide the correct preload:

- Compare the bearing preload you got on the first try with the specified preload of 1.4 - 2.5 Nm (114 - 26 kgf-cm, 12 - 23 inch lbs.).
- If the preload you measure was less than specified, subtract it from the specified preload.
- If the preload you measure was more than specified, subtract it from the specified preload.

For example, with a 2.17 mm (0.0854 inch) thrust shim:

(1) Specified: 2.5 Nm (26 kgf-cm, 23 inch lbs.)
Minus, if you got less: 0.6 Nm (6 kgf-cm, 5 inch lbs.)
Equals: 1.9 Nm (20 kgf-cm, 18 inch lbs.) less than spec

(2) If you got more: 3.3 Nm (34 kgf-cm, 30 inch lbs.)
Minus specified preload: 2.5 Nm (26 kgf-cm, 23 inch lbs.)
Equals: 0.8 Nm (8 kgf-cm, 7 inch lbs.) more than spec


NOTE: Each shim size up or down from standard makes about 0.3-0.4 Nm (3-4 kgf-cm, 2.6-3.5 inch lbs.) difference in preload.

In example (1), your preload was 1.9 Nm (20 kgf-cm, 18 inch lbs.) less than standard, so you need a thrust shim five sizes thicker than standard (try the 2.32 mm (0.0913 inch) thrust shim, and recheck).

In example (2), your preload was 0.8 Nm (8 kgf-cm, 7 inch lbs.) more than standard, so you need a thrust shim two sizes thinner (try the 2.11 mm (0.0831 inch) thrust shim, and recheck).




Thrust Shim Chart

10. Once the carrier bearing preload is correct, install new oil seals in the differential.
11. Reinstall the transmission.