Front Differential: Adjustment

Using ST, screw in the differential side retainer until light contact is felt.
NOTE: Screw in the RH side slightly deeper than the LH side.
1. ST 499787000 WRENCH ASSY
Fig 1: Identifying Special Tool
Courtesy of SUBARU OF AMERICA, INC.
Remove the oil pump housing.
Thoroughly remove the liquid gasket from the case mating surface beforehand.
Install the oil pump housing assembly to the torque converter clutch case, and secure evenly by tightening four bolts.
NOTE: Use an old gasket or an aluminum washer so as not to damage the mating surface of the housing.
1. Tightening torque: 41 N.m (4.2 kgf-m, 30.4 ft-lb)
Fig 2: Identifying Oil Pump Housing Assembly
Courtesy of SUBARU OF AMERICA, INC.
Rotate the drive pinion several times with ST1 and ST2.
1. ST1 498937110 HOLDER
2. ST2 499787700 WRENCH
Fig 3: Rotating Drive Pinion Several Times With ST1 And ST2
Courtesy of SUBARU OF AMERICA, INC.
Tighten the LH differential side retainer until contact is felt while rotating the shaft. Then loosen the RH differential side retainer. Keep tightening the LH differential side retainer and loosening the RH differential side retainer until the pinion shaft can no longer be turned. This is the "zero" state.

Fig 4: Identifying RH Differential Side Retainer
Courtesy of SUBARU OF AMERICA, INC.
After the "zero" state is established, back off the LH differential side retainer 3 notches and secure it with the lock plate. Then back off the RH differential side retainer and retighten until it stops. Rotate drive pinion a few times. Tighten the RH differential side retainer 1-3/4 notches further. This sets the preload. Finally, secure the differential side retainer with its lock plate.

Fig 5: Identifying Lock Plate
Courtesy of SUBARU OF AMERICA, INC.

NOTE: Turning the differential side retainer by one tooth changes the backlash about 0.05 mm (0.0020 in).

Fig 6: Turning Differential Side Retainer By One Tooth Changes
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Turn the drive pinion several rotations with ST1 and check to see if the backlash is within the standard value with ST2, ST3, ST4 and ST5.
1. ST1 499787700 WRENCH
2. ST2 498247001 MAGNET BASE
3. ST3 498247100 DIAL GAUGE
4. ST4 499787500 ADAPTER
5. ST5 498255400 PLATE
1. Backlash: 0.13 - 0.18 mm (0.0051 - 0.0071 in)
Fig 7: Checking Backlash
Courtesy of SUBARU OF AMERICA, INC.
Adjust the tooth contact between front differential and drive shaft. < Ref. to ADJUSTMENT . >