Drive Pinion Shim Selection

Drive Pinion Shim Selection

^ Tools Required
- J 42168-1 Differential Centerline Cylinder
- J 42168-2 Shim Gage Assembly
- J 42168-9 Holding Strap
- J 42168-11 Pinion Housing Centering Spacer
- J 42173 Differential Holding Fixture

Important: The pinion depth adjustment procedure and shim selection must be performed prior to pinion shaft and housing assembly.





1. Install the differential assembly (1) onto the J 42173 (2).

Notice: Refer to Fastener Notice in Service Precautions.

2. Install 4 M8 x 1.25 bolts (3).
^ Tighten the bolts to 25 Nm (18 ft. lbs.).





3. Install the J 42168-1 into the left bearing race bore of the differential housing.





4. Install the J 42168-9 and thumbscrew to the J42168-1. Tighten the thumbscrew until snug.





5. Install the bearing races into the pinion housing/cage (4).
6. Install the J 42168-11 (2), bearings (3 and 6), spacer (5), J 42168-2 (7), and bolt (1) to the pinion housing/cage (4). Tighten the bolt until sung.





7. Install the pinion housing/cage assembly (1) into the differential housing.
The use of M8 x 1.25 dowels or long bolts will ease in pinion housing installation and alignment.





Important: ALL of the pinion housing/cage bolts must be installed in order to obtain an accurate measurement and correct shim selection.

8. Install the pinion housing/cage bolts (1).
^ Tighten the bolts to 25 Nm (18 ft. lbs.).





9. Using a feeler gage, measure the distance between the of 42t68-2 and the J 42168-1. Record the dimension as B1.
10. Subtract the B1 value from a B nominal value of 5 mm (0.197 inch). Record that calculation as B2.
Refer to the applicable calculation tables in Spacer and Shim Specifications.





11. Locate the A1 value (1) on the side of the ring gear.

Important: The A1 value is a manufacturing variation between the ring gear and pinion. The A1 value may be higher, lower, or equal to 103.00 mm (4.055 inch) nominal value. When subtracting the A nominal value from the A1 value, the B3 calculation may compute to a positive, negative, or zero total.

12. Subtract the A nominal value of 103.00 mm (4.055 inch) from the A1 value. Record the calculation as B3.
13. Add the B2 value to the B3 value for the proper pinion housing shim thickness. The B3 value may be a positive, negative, or zero value.
14. Select shims equal to the calculated value. It may be necessary to round the shim or shims total to obtain the proper size shim pack. If the shim thickness calculation is past the midpoint value, round the number higher to the next decimal value.