Multi-plate Clutch: Adjustment

Remove drive plate and driven plate from center differential carrier.
Using the special tool, measure distance "A" from extension case joining surface to multi-plate clutch (LSD) piston.

Fig 1: Measuring Distance "A" From Extension Case Joining Surface To Multi-Plate Clutch (LSD) Piston
Courtesy of SUBARU OF AMERICA, INC.
Using ST, measure height "B" from transmission case joining edge to center differential clutch drum edge.

Fig 2: Measuring Height "B" From Transmission Case Joining Edge To Center Differential Clutch Drum Edge
Courtesy of SUBARU OF AMERICA, INC.
Calculation formula
T = A - B + 0.45 mm

[T = A - B + 0.0177 in]
NOTE:
- Calculation formula for "T" is applied when measuring using ST (398643600 GUAGE, 398744300 GAUGE). When not using ST, apply
  T = (A - alpha + 0.45 mm) - (B - beta)
  
  [T = (A - alpha + 0.0177 in) - (B - beta)].
  
  T: Thrust needle bearing thickness
  
  A: Distance from end of extension case to end of reduction drive shaft
  
  B: Distance from end of transmission case to end of rear drive shaft
  
  alpha: Collar thickness used when measuring "A"
  
  beta: Collar thickness used when measuring "B"
  
  0.45: Gasket thickness (mm)
- Measure multi-plate clutch (LSD) driven and drive plate thickness to find the clearance between measurement value and "T".
  1. Standard value: 0.2 - 0.6 mm (0.008 - 0.024 in)
  2. Limit value: 0.9 mm (0.035 in)
  If outside the standard value, select a pressure plate that will bring clearance within the standard value.
  
  If the clearance is above the limit, replace the drive plate with new one and adjust so that the clearance becomes within the standard value.
Fig 3: Pressure Plates Specifications
Courtesy of SUBARU OF AMERICA, INC.