Clunk

Clunk is due to backlash in the driveline or loose rear suspension components. To determine whether driveline clunk is caused by the axle, make a check of the total axle backlash as follows:
1. Raise the vehicle on a frame or twin post hoist so the wheels are free.
2. To maintain driveline balance, mark rear driveshaft centering socket yoke and rear axle universal joint flange so they may be installed in their original positions.
3. Remove bolts and disconnect driveshaft from the rear axle universal joint flange. Support driveshaft.
4. install Companion Flange Holding Tool T78P-4851-A between the rear axle universal joint flange and a part of the frame or body so that the rear axle universal joint flange cannot move.
5. Lock the LH rear wheel to keep it from turning.





6. Using a torque wrench and locating on one of the lug nuts, rotate RH wheel slowly to a torque of 7-8 Nm (62-70 inch lbs.). Hold a chalk marker on side of tire 304.8 mm (12 inches) from center of wheel.
7. Rotate wheel slowly in opposite direction to a torque of 7-8 Nm (62-70 inch lbs.).
8. Measure the length of the chalk mark which is the total axle backlash. Total axle backlash should be 25.4 mm (1 inch) or less. If the backlash is within this limit, the clunk will not be eliminated by disassembling the axle. Check for these conditions if the backlash is excessive:
a. elongation of the differential pinion shaft holes in the differential case
b. missing differential pinion thrust washer or differential side gear thrust washer
c. galling of the differential pinion shaft and bore
If none of these conditions is present, there may be a loose fit of the axle shafts to the side gear splines. Continue as follows until the correction is made.
9. Install new differential side gears and check the backlash.
10. Install two new axle shafts.
11. Replace the differential case.
12. Install the driveshaft so the index mark on the driveshaft slip yoke is in-line with the index mark on the driveshaft centering socket yoke. This maintains original driveline balance. If vibration exists after installation.
13. Tighten rear axle universal joint flange bolts to 95-130 Nm (70-95 ft. lbs.).