Acura MDX 2002. The car just started making a clunking noise when I first start driving it but then the noise goes away. The clunking noise seems to be coming from the rear of the vehicle. It doesn’t seem to happen when I go over bumps or turn the wheel. It seems to happen after I back up and then start driving forward. Any ideas?
Sticky rear brake pads, parking brake that doesn’t want to release, work stab bar links…
If we don’t use the parking brake does that eliminate that as one of the differentials?
Yes, likely it does eliminate it.
U joints on the driveshaft are shot.
Is that a major repair?
No, but necessary.
I would vote for the U-joints in the driveshaft… When you reverse the torque of the driveshaft will load the U-joint in the opposite direction and if there is slack or play in the U-joint it will show that slack when you then move forward.
You should be able to test this theory by putting the vehicle in reverse with your foot on the brake and then putting it in drive. Adding a small amount of power with the accelerator will help to load the U-joint further in each gear you select, this may be needed to show or further test the u-joint theory. You can do this test without moving the vehicle at all. If you hear the clunk, you found the problem.
If vehicle movement is needed to hear the clunk, then the issue starts to point at the brakes.