Determining Total Shim Pack Size

Determining Total Shim Pack Size

^ Tools Required
- J26900-13 Magnetic Indicator Base
- J8001 Dial Indicator
- J41793 Master Bearing Discs

Note: If your axle assembly has selective outboard spacers and one 0.76 mm (0.030 inch) shim (each side) between the differential case and bearing cone. Make your measurements with the outboard spacers removed, but with the 0.76 mm (0.030 inch) shim assembled on the differential case trunion placed between the case and the master differential bearings. The selective outboard spacers are available in sizes (thickness) from 5.18 mm (0.2040 inch) to 6.10 mm (0.2400 inch), in 0.08 mm (0.003 inch) increments. The dial indicator should have the capability of making measurements up to 12.7 mm (0.500 inch).

Important: The ring gear must not be installed on the differential case assembly. If the ring gear is installed on the differential case assembly, it must be removed.





1. Install one new 0.689 - 0.838 mm (0.027 - 0.033 inch) inboard shim onto each side of the differential case assembly.
2. Install the J41793 onto each side of the differential case assembly.
3. Install the differential case assembly with the J41793 into the axle housing.

Important: Install the bearing caps into the same position from which each was removed.

4. Install the bearing caps.

Notice: Refer to Fastener Notice in Service Precautions.

5. Install the bearing cap bolts.
^ Tighten the bearing cap bolts finger tight. Do not torque the bolts to specification at this time.
6. Assemble the J8001 and the J26900-13 and install onto the ring gear side of the axle housing.
7. Position the indicator of the J8001 onto the flat surface of the differential case assembly.
8. While pushing the differential case assembly towards the J8001, set the dial of the J8001 to zero.
9. Move the differential case assembly away from the J8001 in order to obtain a reading on the J8001.
Repeat the step until a consistent reading is obtained.
Record the reading. Record the number of thousandths that the dial indicator traveled, not the reading on the dial. This value is the total amount of shim thickness needed for the differential case assembly (Measurement A).
10. Remove the bearing cap bolts.
11. Remove the bearing caps.
12. Remove the differential case assembly and the J41793 from the axle housing.

Important: Do not remove the inboard shims from either side of the differential case assembly. If the shims must be removed, mark the shims accordingly so that they can be reassembled onto the correct side of the differential case assembly.

13. Remove the J41793 from the differential case assembly.

Important: The mating surface of the ring gear and the differential case assembly must be clean and free of burrs before installing the ring gear.

14. Install the ring gear to the differential case assembly.
Align the holes in the differential case assembly and the holes in the ring gear.
15. Install the new ring gear bolts. Tighten the ring gear bolts alternately and in stages, gradually pulling the ring gear onto the differential case assembly.
^ Tighten the ring gear bolts in sequence to 298 Nm (220 lb ft).
16. Install the J41793 to the differential case assembly.
17. Install the differential case assembly with the J41793 into the axle housing.

Important: Install the bearing caps into the same position from which each was removed,

18. Install the bearing caps.
19. Install the bearing cap bolts.
^ Tighten the bearing cap bolts finger tight. Do not torque the bolts to specification at this time.
20. Assemble the J8001 and the J26900-13 and install onto the axle housing.
21. Position the indicator of the J8001 onto to the flat surface of one of the ring gear bolts of the differential case assembly.
22. While pressing the ring gear against the drive pinion, set the dial of the J8001 to zero.
23. Move the differential case assembly away from the pinion in order to obtain a reading on the J8001.
Repeat the step until a consistent reading is obtained.
Record the reading. Record the number of thousandths that the dial indicator traveled, not the reading on the dial. This value is the amount of shim thickness needed for the left (ring gear) side of the differential case assembly (Measurement B).
24. In order to determine the amount of shim thickness needed for the right side of the differential case assembly (Measurement C), subtract the value obtained for the left (ring gear) side of the differential case assembly (Measurement 13) from the total shim pack size required determined (Measurement A).
This value is amount of shim thickness needed for the right side of the differential case assembly without setting the differential side bearing preload and the backlash.
25. Remove the J8001 and the J26900-13 from the axle housing.

Important: Do not remove the inboard shims from either side of the differential case assembly. If the shims must be removed, mark the shims accordingly so that they can be reassembled onto the correct side of the differential case assembly.

26. Remove the J41793 from the differential case assembly.
27. Determine the differential side bearing preload.