Shim Selection

SHIM SELECTION / Front Axle - C205F

NOTE: It is difficult to salvage the differential side bearings during the removal procedure. Install replacement bearings if necessary.

1. Remove side bearings from differential case.
2. Install ring gear, if necessary, on differential case and tighten bolts to specification.
3. Install Dummy Bearings 8398 on differential case.
4. Install differential case in the housing.







5. Insert Dummy Shims 8107 0.118 inch (3.0 mm) starting point shims between both dummy bearings and the housing (Fig. 11).
6. Install the marked bearing caps in their correct positions. Install and snug the bolts.










7. Using a dead-blow hammer to seat the differential dummy bearings to each side of the differential housing (Fig. 12) and (Fig. 13).







8. Thread Pilot Stud C-3288-B into rear cover bolt hole below ring gear (Fig. 14).
9. Attach Dial Indicator C-3339 to post and position dial indicator plunger on a flat surface on a ring gear bolt head (Fig. 14).







10. Push firmly and hold differential case to pinion side of axle housing (Fig. 15) and zero dial indicator.







11. Push firmly and hold differential case to the ring gear side and record dial indicator reading (Fig. 16).
12. Add the dial indicator reading to the starting point shim thicknesses to determine the total shim thickness necessary to achieve zero differential end play.
13. Add 0.2 mm (0.008 inch) to the zero end play total. This new total represents the thickness of shims necessary to compress, or preload the new bearings when the differential is installed.
14. Rotate dial indicator out of the way on pilot stud.
15. Remove differential case, dummy bearings, and starting point shims from the housing.
16. Install the pinion in the axle housing. Install the companion flange and establish the correct pinion rotating torque.
17. Install differential case and Dummy Bearings in axle housing with a single dummy shim on the ring gear side of the axle and tighten retaining cap bolts.
18. Position the dial indicator plunger on a flat surface between the ring gear bolt heads (Fig. 14).
19. Push and hold differential case toward pinion.
20. Zero dial indicator face to pointer.
21. Push and hold differential case to ring gear side of the housing.
22. Record dial indicator reading.
23. Subtract 0.05 mm (0.002 inch) from the dial indicator reading to compensate for backlash between ring and pinion gears. Add the resulting measurement to the thickness of the single starting point shim. This total is the thickness of shim required to achieve proper backlash.
24. Subtract the backlash shim thickness from the total preload shim thickness. The remainder is the shim thickness required on the pinion side of the axle housing.
25. Rotate dial indicator out of the way on pilot stud.
26. Remove differential case, dummy bearings and dummy shim from the housing.
27. Install new side bearing cones and cups on differential case.
28. Install Spreader W-129-B and Adapter Plates 8142-A on the housing and spread open enough to receive differential case.
29. Place the side bearing shims in the differential housing against the housing shoulder.
30. Install the differential case in the housing.
31. Rotate the differential case several times to seat the side bearings.







32. Position the indicator plunger against a ring gear tooth (Fig. 17).
33. Push and hold ring gear upward while not allowing the pinion gear to rotate.
34. Zero dial indicator face to pointer.







35. Push and hold ring gear downward while not allowing the pinion gear to rotate. Dial indicator reading should be between 0.12 mm (0.005 inch) and 0.20 mm (0.008 inch). If backlash is not within specifications transfer the necessary amount of shim thickness from one side of the differential housing to the other (Fig. 18).
36. Verify differential case and ring gear runout by measuring ring to pinion gear backlash at eight locations around the ring gear. Readings should not vary more than 0.05 mm (0.002 inch). If readings vary more than specified, the ring gear or the differential case is defective.
After the proper backlash is achieved, perform the Gear Contact Pattern procedure.