Subaru Legacy IV (2008 year). Manual - part 686

4AT-92

Drive Pinion Shaft Assembly

AUTOMATIC TRANSMISSION

8) Measure the dimension “B” of the drive pinion
shaft.
ST

398643600

GAUGE

9) Calculate the thickness “t” mm (in) of the drive
pinion shim.
t = 6.5

r0.0625 (0.256r0.0025) – (B – A)

10) Select three or less shims from following table.

E: INSPECTION

• Make sure that all component parts are free of
scratches, holes and other faults.
• Adjust the tooth alignment. <Ref. to 4AT-92, AD-
JUSTMENT, Drive Pinion Shaft Assembly.>

F: ADJUSTMENT

1) Remove the liquid gasket from the mating sur-
face completely.
2) Install the oil pump housing assembly to the con-
verter 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)

3) Rotate the drive pinion a few times using ST1
and ST2.
ST1

498937110

HOLDER

ST2

499787700

WRENCH

4) Adjust the drive pinion and hypoid driven gear
backlash. <Ref. to 4AT-99, ADJUSTMENT, Front
Differential Assembly.>

B Measured value

Drive pinion shim

Part No.

Thickness mm (in)

31451AA050

0.150 (0.0059)

31451AA060

0.175 (0.0069)

31451AA070

0.200 (0.0079)

31451AA080

0.225 (0.0089)

31451AA090

0.250 (0.0098)

31451AA100

0.275 (0.0108)

B

AT-00204

AT-00205

AT-00206

ST2

ST1

4AT-93

Drive Pinion Shaft Assembly

AUTOMATIC TRANSMISSION

5) Apply lead-free red dye evenly on the surface of
three to four teeth of the hypoid driven gear. Rotate
the drive pinion back and forward several times.
Remove the oil pump housing, and check the teeth
contact pattern.
If the teeth contact is inappropriate, adjust the
backlash or thickness of the shim. <Ref. to 4AT-99,
ADJUSTMENT, Front Differential Assembly.>
• Correct tooth contact
Check item: Tooth contact surface is slightly
shifted toward the toe side under a no-load con-
dition. (When driving, it moves towards the heel
side.)

• Face contact
Check item: Backlash is too large.
Contact pattern

Corrective action: Increase thickness of drive pin-
ion height adjusting washer in order to bring drive
pinion close to hypoid driven gear.

• Flank contact
Check item: Backlash is too small.
Contact pattern

Corrective action: Reduce the thickness of pinion
height adjusting washer according to the procedure
for bringing drive pinion away from hypoid driven
gear.

(A) Toe side

(B) Heel side

(A)

(B)

MT-01401

AT-00208

AT-00212

AT-00209

AT-00213

4AT-94

Drive Pinion Shaft Assembly

AUTOMATIC TRANSMISSION

• Toe contact (inside contact)
Check item: Contact area is too small.
Contact pattern

Corrective action: Reduce the thickness of pinion
height adjusting washer according to the procedure
for bringing drive pinion away from hypoid driven
gear side.

• Heel contact (outside end contact)
Check item: Contact area is too small.
Contact pattern

Corrective action: Increase thickness of pinion
height adjusting washer according to the proce-
dures for moving the drive pinion closer to the hy-
poid driven gear.

6) If tooth contact is correct, mark the differential
side retainer position and loosen. After fitting a new
O-ring and oil seal, screw in the differential side re-
tainer to the marked position. Tighten the lock plate
with specified torque.

Tightening torque:

25 N·m (2.5 kgf-m, 18.4 ft-lb)

AT-00210

AT-00213

(A) Lock plate

AT-00211

AT-00212

AT-00214

(A)

4AT-95

Front Differential Assembly

AUTOMATIC TRANSMISSION

33.Front Differential Assembly

A: REMOVAL

1) Remove the transmission assembly from vehicle
body. <Ref. to 4AT-35, REMOVAL, Automatic
Transmission Assembly.>
2) Pull out the torque converter clutch assembly.
<Ref. to 4AT-67, REMOVAL, Torque Converter
Clutch Assembly.>
3) Remove the input shaft.

4) Lift up the lever on the rear side of transmission
harness connector, and then remove it from the
stay.
5) Remove the inhibitor switch connector from the
stay.
6) Remove the oil charge pipe. <Ref. to 4AT-66,
REMOVAL, Oil Charge Pipe.>
7) Remove the ATF inlet and outlet pipes. <Ref. to
4AT-62, REMOVAL, ATF Cooler Pipe and Hose.>
8) Separate the converter case from the transmis-
sion case. <Ref. to 4AT-80, REMOVAL, Converter
Case.>
9) Remove the seal pipe.
10) Remove the differential side retainers using
ST.
ST

18630AA010

WRENCH COMPL RETAINER

NOTE:
• ST

WRENCH ASSEMBLY (499787000) can

also be used.
• Hold the differential case assembly by hand to
avoid damaging the retainer mounting hole of the
converter case.
11) Remove the front differential assembly while
being careful not to damage the attachment part of
the retainer.

B: INSTALLATION

1) Install the front differential assembly to the case.

NOTE:
Be careful not to damage the inside of the convert-
er case (especially the mating surface of the differ-
ential side retainer).

2) Install the O-ring to left and right side differential
retainers.
3) Install the differential side retainers using ST.
<Ref. to 4AT-99, ADJUSTMENT, Front Differential
Assembly.>
ST

18630AA010

WRENCH COMPL RETAINER

NOTE:
ST

WRENCH ASSEMBLY (499787000) can also

be used.
4) Adjust the backlash of the front differential. <Ref.
to 4AT-99, ADJUSTMENT, Front Differential As-
sembly.>
5) Install the lock plate.

Tightening torque:

25 N·m (2.5 kgf-m, 18.4 ft-lb)

AT-00114

(A) Front differential ASSY

(A) Lock plate

AT-00215

(A)

AT-00214

(A)