Subaru IMPREZA 2002 Service Manual page 300

FRONT DIFFERENTIAL ASSEMBLY
MANUAL TRANSMISSION AND DIFFERENTIAL
3. TOOTH CONTACT OF HYPOID GEAR
I
The drive pinion shim selected before is too thin.
Adjust until the teeth contact is correct.
Backlash is excessive.
To reduce backlash, loosen holder on the upper
side (case right side) and turn in the holder on the
lower side (case left side) by the same amount.
Backlash is insufficient.
To increase backlash, loosen holder on the lower
side (case left side) and turn in the holder on the
upper side (case right side) by the same amount.
B3MQO72
The drive pinion shim selected before is too
thick.
Reduce its thickness.
03M0073
Increase its thickness.
B3MOQ74
MT-76