Differential Case: Testing and Inspection

Special Tools:

1. Remove the front axle assembly. For additional information, refer to Axle Assembly-Front.

2. Install the axle in the Bench Mounted Holding Fixture.

3. NOTE: Place a drain pan under the axle to catch fluid.

Drain the axle fluid.
1 Remove the ten bolts.
2 Remove the differential cover.

4. Remove the axle shaft using a jerking motion.

5. Install and position a dial indicator with bracken

6. NOTE: If the ring gear runout exceeds specification, the cause may be a warped ring gear, a damaged differential case, loss of differential bearing preload or a damaged axle housing.

Check and record the ring gear runout.
1 Rotate the differential case.
2 Check and record the ring gear runout.

7. Remove the dial indicator with bracketry.

8. CAUTION: The matched numbers or letters stamped on both the differential bearing caps and axle housing must correspond upon assembly.

Remove the differential bearing caps.
1 Remove the four bolts.
2 Remove the differential bearing caps.

9. CAUTION: Housing Spreader Adapter bolts have a minimum thread engagement.

Install the Housing Spreader Adapter Set.

10. NOTE: Make sure the indicator needle is in spreader adapter hole.

Install the differential housing spreader and dial indicator with bracketry.
1 Install the differential housing spreader.
2 Install the dial indicator with bracketry and the Clutch Housing Alignment Adapter.

11. CAUTION: Over-spreading can cause damage to the axle housing.

Spread the axle housing.
1 Adjust the dial indicator to zero.
2 Tighten the spreader screw until the axle housing is spread.
3 Remove the dial indicator with bracketry and the Clutch Housing Alignment Adapter.

12. CAUTION: Wood blocks must be used to avoid axle housing damage.

NOTE: Keep the shims and bearing cups in order

Remove the differential case from the axle housing.
1 Position the wood blocks.
2 Use two pry bars and push down on the pry bars.
3 Remove the differential case.
4 Remove a differential housing spreader and Housing Spreader Adapter Set.

13. Measure the pinion bearing preload.
- Use a Nm (inch lbs.) beam type torque wrench to measure the torque required to maintain rotation of the pinion and record the measurement for reference during assembly.

14. Index mark the pinion flange to the pinion stem.

15. Use the Companion Flange Holding Tool to remove the pinion nut.

16. Use the 2-jaw puller to remove the pinion flange.

17. WARNING: Gear teeth may have sharp edges. When handling gear, use care to avoid personal injury.

CAUTION: Use a soft mallet to drive the pinion out of the axle housing.

Remove the pinion from the axle housing.
1 Hold the pinion inside the axle housing.
2 Use a soft face hammer to remove the pinion from the axle housing.

18. Install the differential bearing caps, and tighten the four bolts.

19. Rotate the differential case to ensure free rotation.

20. Install and position the dial indicator with bracketry.

21. NOTE: If the ring gear runout is within specification, the original out-of-specification runout was caused by insufficient differential bearing preload.

Check and record the ring gear runout.
1 Rotate the differential case.
2 Check and record the ring gear runout.

22. Position the differential case with the differential bearing cups in the axle housing.

23. Install the differential bearing shim on the LH side.

24. Install the LH differential bearing cap.
1 Position the LH differential bearing cap.
2 Install the two bolts finger-tight.

25. Install progressively larger differential bearing shims on the RH side until the largest differential bearing shim can be assembled with a slight drag feel.

26. Remove the dial indicator with bracketry.

27. Remove the differential bearing caps.
1 Remove the four bolts.
2 Remove the differential bearing caps.

28. Remove the differential case from the axle housing.

29. Remove the ring gear.
1 Remove the eight ring gear bolts.
2 Use a drift punch to separate the ring from the differential case.

30. NOTE: Use of proper shims is necessary for this step.

Install the differential case in the axle housing without the ring gear.
1 Position the differential case.
2 Position the differential bearing caps. Install the four bolts.

31. Install and position the dial indicator with bracketry.
1 Rotate the differential case to ensure the differential bearings are properly seated.
2 Install and position the dial indicator with bracketry.

32. NOTE: If runout is within specification, install a new ring gear and pinion. If runout exceeds specification, the ring gear is true and the concern is due to either a damaged differential case or differential bearings. Inspect the differential bearings. If the differential bearings are not damaged, replace both the differential case and the differential bearings.

Measure the differential case runout without the ring gear.
1 Rotate the differential case.
2 Check and note the differential case runout.

33. NOTE: If runout is now within specification, use new differential bearings for assembly. If runout is still excessive, the axle housing is damaged and must be replaced.

Recheck runout with the new differential case and differential bearings.
1 Rotate the differential case.
2 Recheck and note the differential case runout.
34. Assemble the axle.
35. Install the front axle assembly.
36. Fill the axle assembly with Motorcraft SAE 80W90 Thermally Stable 4x4 Axle Lubricant meeting Ford specification WSP-M2C197-A.