Experts: I'm going insane, I can't figure out this clunk/thud.

[Mook613]

Is it only on lateral changes or do you hear it going over bumps as well?

Your diff is attached to your rear subframe which is held in place by some big bushings. I'm thinking that it could be those bushings, but if so I would think that you'd hear it going over bumps as well.

Other things to check would be to check for something loose in your trunk, perhaps in the spare wheel well.

[Sail Boat]

Hey everyone-

This noise is driving me insane.

Whenever I tap the throttle, I get two successive soft clunking noises: one immediately after applying throttle and another when letting off. It sounds like its coming from the rear, but I can't be sure.

I've done a lot in attempt to remedy the situation. Originally, I suspected the differential, which was a 4.10 open with a standard bushing. I upgraded the diff to a rebuilt 4.10 LSD with a powerflex urethane bushing and made sure the halfshafts and diff bolts were torqued properly.

Noise persisted.

Next, I replaced the transmission mounts and checked the engine mounts. I even unbolted the flex disc to check the trans output shaft, but there was only a few millimeters of rotational play in either direction, which I have read is totally normal.

Noise persisted.

I felt discouraged at this point, since this indicated to me that the U-Joints, Flex Disc, or Center Support Bearing were likely shot. I decided to go ahead and replace everything in the drive line with a remaned driveshaft with serviceable U-Joints built by a BMW driveshaft specialist, a Febi Flex Disc and a Febi CSB.

The noise persists.

To be honest, I'm pretty confused. I replaced everything that is known to cause a "clunk" noise with throttle application. I'm starting to think that I'm trying to silence a noise that's normal.

Any other recommendations? Thanks!