Component Tests and General Diagnostics

Driveline System

Component Tests

Runout Check - Half-Round Companion Flange (Ford Axles Only)

NOTICE: Pinion bearing preload must be reset if the pinion nut has been loosened or damage to the component will result.

1. Raise the vehicle on a twin-post hoist that supports the rear axle.

2. Remove the driveshaft. Refer to Driveshaft Diagrams.

3. Check the pinion flange for damage.

4. Insert the correct size Drive Pinion Flange Pin Gauge.





5. Position the Drive Pinion Flange Runout Gauge on the pinion flange.





6. Align the holes on the Dial Indicator Gauge with Holding Fixture with the holes in the pinion flange and install the bolts and nuts.





7. NOTE: Accurate tool setup will result in accurate final readings.

Position the Dial Indicator Gauge with Holding Fixture as shown. Adjust and lightly tighten the mounting bolts and nuts so the gauge runout is 0.254 mm (0.010 in) or less.





8. Position the Dial Indicator Gauge with Holding Fixture on the edge of the gauge. Turn the drive pinion runout gauge, and locate and mark the high spot on the pinion flange with yellow paint.





If the flange runout exceeds 0.25 mm (0.010 in), remove the pinion flange, reindex the flange one-half turn on the pinion and reinstall it.

9. Check the runout again. If necessary, reindex the flange until an acceptable runout is obtained. If the flange runout is still more than 0.25 mm (0.010 in), install a new pinion flange.





10. If excessive runout is still evident after installing the new pinion flange, install a new ring and pinion. Repeat the above checks until the runout is within specifications.

11. Install the driveshaft. Refer to Driveshaft Diagrams.

Differential Check - Tractech(R) Truetrac(R) Road Test (Dana)

1. Shift the transmission into NEUTRAL.

2. Raise and support the vehicle. Refer to Jacking and Lifting Service and Repair.

3. Spin either rear wheel.
- Both wheels must spin with a fluid motion. Any feeling of gripping and release/roughness indicates that additional inspection of the axle assembly is necessary. For information about axle disassembly and inspection, refer to Rear Drive Axle/Differential - Dana 80 Testing and Inspection, Rear Drive Axle/Differential - Dana S110 and S130 Testing and Inspection or Rear Drive Axle/Differential - Ford 10.50-Inch Ring Gear Testing and Inspection.

4. Shift the transmission into gear.

5. Spin either rear wheel.
- The other wheel must spin with a fluid motion in the opposite direction and at the same speed of the wheel being spun. Any feeling of gripping and release/roughness indicates that further inspection of the axle assembly is necessary. For information about axle disassembly and inspection, refer to Rear Drive Axle/Differential - Dana 80 Dana 80 and Testing and Inspection, Rear Drive Axle/Differential - Dana S110 and S130 Differential Case and Ring Gear and Testing and Inspection or Rear Drive Axle/Differential - Ford 10.50-Inch Ring Gear Ford 10.50-Inch Ring Gear and Testing and Inspection.

Contact Pattern Location

In general, desirable ring gear tooth patterns must have the following characteristics:

- Drive pattern on the drive side differential ring gear well centered on the tooth.
- Coast pattern on the coast side differential ring gear well centered on the tooth.
- Clearance between the pattern and the top of the tooth.
- No hard lines where the pressure is high.

Acceptable differential ring gear tooth patterns for all axles.





Correct backlash with a thinner pinion position shim as necessary.





Correct backlash with a thicker pinion position shim as necessary.





Correct pinion position shim that requires a decrease in backlash.





Correct pinion position shim that requires an increase in backlash.