Clunk

WARNING: THE ELECTRICAL POWER TO THE AIR SUSPENSION SYSTEM MUST BE SHUT OFF PRIOR TO HOISTING, JACKING OR TOWING AN AIR SUSPENSION VEHICLE. THIS CAN BE ACCOMPLISHED BY TURNING OFF THE AIR SUSPENSION SWITCH LOCATED IN THE RH KICK PANEL AREA. FAILURE TO DO SO MAY RESULT IN UNEXPECTED INFLATION OR DEFLATION OF THE AIR SPRINGS WHICH MAY RESULT IN SHIFTING OF THE VEHICLE DURING THESE OPERATIONS.

1. Raise and support the vehicle.
2. Remove the driveshaft.





3. Use Companion Flange Holding Tool to clamp one end of a rigid bar or pipe to the rear axle companion flange.
4. Clamp the other end of the bar or pipe to the frame or body member in order to prevent movement of the rear axle companion flange.
5. Lower the vehicle so that one rear wheel is resting on a wheel chock to prevent it from turning. The other rear wheel will be used to measure total rear axle backlash.
6. Rotate the free wheel slowly, by hand, until the feeling of driving the rear axle is encountered. Mark with a crayon or chalk on the side of the tire 305 mm (12 inches) from the center of the wheel. Rotate the wheel slowly in the opposite direction until the feeling of driving the rear axle is encountered again.
7. Measure the length of the crayon or chalk mark on the tire. If the length of the mark is 25.4 mm (1 inch) or less, the rear axle backlash is within allowable limits.
8. If the chalk mark is greater than 25.4 mm (1 inch), check for these conditions:
- Elongation of the differential pinion shaft holes in the differential case.
- Missing differential, pinion or differential side gear thrust washer.
- Galling of the differential pinion shaft and bore.
- Excessive ring gear and pinion backlash. Follow the procedure for the type of rear axle to check backlash.