Side Bearing Preload Adjustment

^ Tools Required:
- J 22779 Side Bearing Backlash Gauge

^ The differential side bearing preload adjustment must be made before installing the pinion.
^ The differential case side bearing preload is adjusted by changing the thickness of the left and right shims equally. This procedure will maintain the original backlash.
^ Production shims are cast iron and are not to be reused. Measure the production shims and spacers one at a time and add the measurements together to obtain the sizes of the left and right shim packs.
^ Service spacer thickness is nominal at 4.32 mm (0.170 inch).
^ Service shims are available from 1.02 mm to 2.54 mm (0.040 to 0.100 inch) in increments of 0.101 mm (0.004 inch).
^ Make sure the side bearing surfaces are clean and free of burrs.

1. Place the case with the bearing cups installed into the axle housing.
A. Lubricate the axle bearings with axle lubricant.
B. Support the case to keep it from falling into the axle housing.





2. Insert J 22779 between the axle housing and the left bearing cup.





3. Move the tool Back and forth in the bore while turning the adjusting nut to the right until a noticeable drag is produced.
A. Tighten the lock bolt on the side of the tool.
B. Leave the tool in place.
4. Install a service spacer and service shim between the right bearing cup and axle housing.
5. Determine bearing preload by inserting progressively larger feeler gauge sizes between the axle housing and service shim.
A. Push the feeler gauge downward so it contacts the shim at the top and bottom, and then contacts the axle housing.
B. The point just before additional drag begins is the correct feeler gauge thickness. This is the zero setting without preload.
6. Remove the strap, J 22779, service spacer, service shim, feeler gauge, and differential case from the axle housing.





7. Measure J 22779 in three places using a micrometer. Average the readings.
8. Add the dimensions of the right side service spacer, service shim, and feeler gauge.





9. For an initial backlash setting, move the ring gear away from the pinion by subtracting 0.25 mm (0.010 inch) from the ring gear side shim pack and adding 0.25 mm (0.010 inch) to the shim pack on the opposite side.
10. To obtain the proper preload on the side bearings add 0.10 mm (0.004 inch) to the measurement of each shim pack.
11. Install the differential. Refer to BACKLASH ADJUSTMENT.

NOTICE: Proper pinion depth setting is a two-step procedure.
1. Setup dimension arrived at with the indicator to be considered a starting point.
2. Gear tooth pattern check is necessary to "fine tune" the pinion depth and may indicate additional shim changes to the pinion stem. Both procedures must be performed to ensure proper axle performance and prevent system damage.