Drive Pinion Shaft Assembly: Adjustment

WARNING: This page is about a different variant/trim than selected.

Inspect and adjust the hypoid driven gear-to-drive pinion backlash. <Ref. to HYPOID GEAR BACKLASH , ADJUSTMENT, Front Differential Assembly.>
Apply a thin uniform coat of lead-free red dye on the surfaces of 3 or 4 hypoid driven gear teeth.

Fig 1: Applying Thin Uniform Coat On Hypoid Driven Gear Teeth Surfaces
Courtesy of SUBARU OF AMERICA, INC.
Install the drive pinion shaft assembly to the clutch housing, and tighten at least 4 bolts.
NOTE: Install with the remaining liquid gasket, so that the clutch housing and the adapter plate will not be damaged.

Tightening torque:

50 N.m (5.1 kgf-m, 36.9 ft-lb)
Turn a few times using the ST.
ST 18631AA000 HANDLE

Fig 2: Turning Drive Pinion Shaft
Courtesy of SUBARU OF AMERICA, INC.
Remove the drive pinion shaft assembly, and inspect the mating condition of the teeth. If the tooth contact is not correct, adjust the backlash or shim thickness.
- Correct tooth contact
  Check item: Tooth contact surface is slightly shifted toward the toe side under a no-load condition. (When driving, it moves towards the heel side.)
  
  Fig 3: Identifying Tooth Contact Pattern (Toe Side And Heel Side)
  Courtesy of SUBARU OF AMERICA, INC.
- Face contact
  Check item: Backlash is too large.
  
  Contact pattern
  
  Fig 4: Identifying Tooth Contact Pattern (Large)
  Courtesy of SUBARU OF AMERICA, INC.
  
  Corrective action: Tighten the side retainer to move the driven gear closer to the drive pinion shaft.
  
  Fig 5: Moving Driven Gear Closer To Drive Pinion Shaft
  Courtesy of SUBARU OF AMERICA, INC.
- Flank contact
  Check item: Backlash is too small.
  
  Contact pattern
  
  Fig 6: Identifying Tooth Contact Pattern (Small)
  Courtesy of SUBARU OF AMERICA, INC.
  
  Corrective action: Loosen the side retainer to move the driven gear away from the drive pinion shaft.
  
  Fig 7: Moving Driven Gear Away From Drive Pinion Shaft
  Courtesy of SUBARU OF AMERICA, INC.
- Toe contact (inside contact)
  Check item: Teeth contact area is too small.
  
  Contact pattern
  
  Fig 8: Identifying Tooth Contact Pattern (Toe Inside)
  Courtesy of SUBARU OF AMERICA, INC.
  
  Adjustment: Reduce the thickness of the drive pinion shim according to the procedure for moving the drive pinion away from the driven gear.
  
  Fig 9: Moving Drive Pinion Away From Driven Gear
  Courtesy of SUBARU OF AMERICA, INC.
- Heel contact (outside end contact)
  Check item: Teeth contact area is too small.
  
  Contact pattern
  
  Fig 10: Identifying Tooth Contact Pattern (Heel Outside)
  Courtesy of SUBARU OF AMERICA, INC.
  
  Adjustment: Increase thickness of the drive pinion shim according to the procedures for moving the drive pinion closer to the driven gear.
  
  Fig 11: Moving Drive Pinion Closer To Driven Gear
  Courtesy of SUBARU OF AMERICA, INC.