MPT Model

1. ST 398643600 GAUGE
2. L = Measured value - 15 mm
3. (L = Measured value - 0.59 in)

Fig 1: Measuring Distance "L" From End Of Extension Case & Rear Drive Shaft

Courtesy of SUBARU OF AMERICA, INC.

1. A:  Measured value
2. B:  ST thickness [15 mm (0.59 in)]
3. L:  Distance from end of extension case to end of rear drive shaft

1. l  = Measured value - 50 mm
2. (l  = Measured value - 1.97 in)
3. ST1 398643600 GAUGE
4. ST2 499577000 GAUGE

Fig 2: Measuring Distance From Transmission Case Mating Surface To Reduction Drive Gear End Surface

Courtesy of SUBARU OF AMERICA, INC.

1. A:  Measured value
2. B:  ST thickness [50 mm (1.97 in)]
3. l:  Distance from end of transmission case to end of reduction drive gear

When clearance is at 0.05 mm (0.0020 in) and 0.25 mm (0.0098 in), then select a suitable thrust needle bearing from the table.

1. H = (L + 0.45 mm) - l  - T
2. [H = (L + 0.0177 in)- l  -T]
3. T  : Thrust needle bearing thickness
4. L:  Distance from end of extension case to end of rear drive shaft
5. 0.45 mm (0.0177 in): Gasket thickness
6. l:  Distance from end of transmission case to end of reduction drive gear
7. H:  Shim clearance
8. 0.05-0.25 mm (0.0020-0.0098 in)

Example: 

1. When, L = 18.60 mm (0.7323 in), l  = 15.05 mm (0.5925 in)
2. Calculation when clearance is 0.05 mm (0.0020 in)
3. H = (18.60 + 0.45) - 15.05 - 0.05 = 3.95
4. [H = (0.7323 + 0.0177) - 0.5925 - 0.0020 = 0.1555]
5. Calculation when clearance is 0.25 mm (0.0098 in)
6. H = (18.60 + 0.45) - 15.05 - 0.25 = 3.75
7. [H = (0.7323 + 0.0177) - 0.5925 - 0.0098 = 0.1476]

After calculation, the value of "H" becomes between 3.75 and 3.95, therefore select bearing thickness of 3.8.