Front Differential Assembly: Adjustment

Using the ST, screw-in the differential side retainer until resistance is felt.
NOTE:
- Screw-in the RH side slightly deeper than the LH side.
- ST WRENCH ASSY (499787000) can also be used.
ST 18630AA010 WRENCH COMPL RETAINER
Remove the oil pump housing.
Remove the liquid gasket from the mating surface completely.
Install the oil pump housing assembly to the converter case, and secure them by tightening the four bolts evenly.
NOTE: Use an old gasket or aluminum washer to prevent damaging the mating surface of the housing.

Tightening torque:

41 N.m (4.2 kgf-m, 30.2 ft-lb)

Fig 1: Identifying Oil Pump Housing Assembly
Courtesy of SUBARU OF AMERICA, INC.
Rotate the drive pinion a few times using ST1 and ST2.
ST1 498937110 HOLDER

ST2 499787700 WRENCH

Fig 2: Rotating Drive Pinion Using Special Tools
Courtesy of SUBARU OF AMERICA, INC.
Tighten the LH differential side retainer by rotating the shaft until resistance is felt. Then loosen the RH side differential side retainer. Tighten the LH differential side retainer until the pinion shaft no longer turns, and continue to loosen the RH side. This is the "zero" state.

Fig 3: Identifying Differential Side Retainer
Courtesy of SUBARU OF AMERICA, INC.
After reaching the "zero" state, loosen the LH differential side retainer by 3 notches and secure it with the lock plate. Then after returning the RH differential side retainer, retighten until it stops. Rotate the drive pinion 2 or 3 times. Tighten the RH differential side retainer further by 1 and 3/4 notches. This sets the preload. Finally, secure the differential side retainer with the lock plate.

Fig 4: Identifying Lock Plate
Courtesy of SUBARU OF AMERICA, INC.

NOTE: Turning the differential side retainer by one notch (A) changes the backlash approx. 0.05 mm (0.0020 in).

Fig 5: Turning Differential Side Retainer By One Notch
Courtesy of SUBARU OF AMERICA, INC.
Install the SUBARU genuine axle shaft to the left and right sides of the front differential.
Part No. 38415AA000 Axle shaft
Turn the drive pinion a few times with ST1 and check to see if the backlash is within the specified value, using ST2, ST3, ST4 and ST5.
ST1 499787700 WRENCH

ST2 498247001 MAGNET BASE

ST3 498247100 DIAL GAUGE

ST4 499787500 ADAPTER

ST5 498255400 PLATE

Backlash:

0.13 - 0.18 mm (0.0051 - 0.0071 in)

Fig 6: Turning Drive Pinion Using ST1
Courtesy of SUBARU OF AMERICA, INC.
Adjust the teeth contact of the front differential and drive pinion shaft. < Refer to ADJUSTMENT , Drive Pinion Shaft Assembly. >