Gear Tooth Contact Pattern Inspection
Gear Tooth Contact Pattern Inspection^ Tools Required
- J 39446 ABS Exciter Ring Protector Kit
Notice: It is very important that tooth contact be tested after the differential is taken apart. Variations in the differential or differential drive pinion gear inner bearing may cause the differential drive pinion gear to be too far away from, or close to, the differential ring gear. Therefore, the tooth contact pattern must be tested and corrected, (if necessary) to prevent gear noise.
1. Clean all of the dirt from the area of the rear axle housing cover before removing the rear axle housing cover.
2. Remove the rear axle housing cover.
3. Wipe the oil out of the rear axle housing.
4. Carefully clean each tooth of the ring gear.
5. Install the J 39446 to the speed sensor reluctor wheel on vehicles not equipped with traction control rear axles.
6. Using a medium stiff brush, apply a mixture of gear marking compound sparingly to all of the ring gear teeth. The area of tooth contact of the differential drive pinion gear should remain visible.
Notice: Refer to Fastener Notice in Service Precautions.
7. Tighten the differential carrier bearing cap bolts/screws.
^ Tighten the differential carrier bearing cap bolts/screw to 75 Nm (55 ft. lbs.).
Important: A test made without properly loading the gears will not give a satisfactory pattern.
8. Apply the park brake until a torque of 14 Nm (10 ft. lbs.) is required in order to rotate the drive pinion gear.
9. Use the following procedure in order to obtain a ring gear tooth contact pattern:
9.1. Using a wrench on the pinion gear yoke, rotate the assembly through three complete revolutions of the ring gear.
9.2. Using a wrench on the pinion gear yoke, rotate the assembly through three complete revolutions of the ring gear in the opposite direction.
10. Inspect the differential ring gear teeth for a tooth contact pattern (1).
11. The pattern is acceptable if the area of differential drive pinion gear contact (1) remains in the center of the differential ring gear tooth. If the pattern is not acceptable, proceed to Step 14.
12. If the differential ring gear tooth pattern is acceptable, remove the J 39446.
13. Install the rear axle housing cover.
14. Inspect the differential ring gear teeth for a low flank contact pattern (2).
15. If this contact pattern exists, repair the low flank contact by decreasing the shim thickness of the bearing on the differential drive pinion gear. This moves the smaller diameter of the contact (2) out toward the center line (1) of the differential ring gear.
16. Remove the J 39446.
17. Install the rear axle housing cover.
18. Inspect the differential ring gear teeth for a heel contact pattern (1).
19. If this contact pattern exists, repair the heel contact by decreasing the backlash.
20. Remove the J 39446.
21. Install the rear axle housing cover.
22. Inspect the differential ring gear teeth for a high face contact pattern (2).
23. If this contact pattern exists, repair the high face contact by increasing the thickness of the bearing shim of the differential drive pinion gear. This moves the area of differential drive pinion gear contact out toward the differential ring gear center line (1).
24. Remove the J 39446.
25. Install the rear axle housing cover.
26. Inspect the differential ring gear teeth for a toe contact pattern (1).
27. If this contact pattern (1) exists repair the heel contact by increasing the backlash. This moves the area of differential drive pinion gear contact toward the heel.
28. Remove the J 39446.
29. Install the rear axle housing cover.