Drive Train Clunking noise (on and off the clutch in first/reverse.)

Hello all, I have a clunk from what sounds like my drivetrain when pulling into the garage or at a drive through. Below is the perfect description copied from another thread that didn't have any posts on it.

-Put car in first or reverse
-Accelerate a bit, but not enough that one fully releases the clutch before slowing again - say backing out of a parking space, pulling one carlength closer to a stop sign, that sort of thing.
-Upon releasing the gas and pushing the clutch back to the floor...clunk clunk clunk. Metallic-sounding, like something rocking back and forth when suddenly unloaded.
-If staying on the gas and depressing the clutch so RPMs rise...no noise.
-If accelerating and fully releasing clutch and driving away, no noise.
-When slowing, even downshifting, no noise.
-Letting off the throttle at speed, any time the clutch pedal is fully released, no noise.

Car has a brand new clutch, flywheel, and pressure plate so its not clutch chatter.

I am thinking its either the driveshaft u joint which I've looked at and didn't see any problems or the engine/diff mounts. The rear diff appears to have red (aftermarket) mounts.


IDEAS??!!

Mine does that a bit too. I suspect it is lash in the differential or the rear u joint on the draiveshaft. The best wat to try to replicate is to raise the rear wheels off the ground and twist the driveshaft with the car in neutral, e-brake off. There is some play in the diff, which is normal. Perhaps try removing the rear of the driveshaft from the diff (if you pull the front yolk out, transmission fluid will leak out). From there, try the rear flange/u-joint on the driveshaft and feel for any notchy or 'catching' in the u-joint's movement. IF there is, look for another used driveshaft or find a shop to rebuild it. After that, grab the input flange on the diff and twist it it back and forth. Some play is ok, but if you feel the teeth shearing, you could have some bearing issues developing in the pumpkin.

Lastly, consider if your engine mounts have been replaced. at 20 years old, your '96 may still be on the origiial engine mounts. If they are torn, the short gearing in reverse and first may be exacerbating their condition where the engine is laying over more in the bay.

Forgot to add, I have the ES diff bushings too, so they are stiffer and take a lot of movement out of the driveline. They also send more NVH through the car as well, so may me a little more sensitive to the driveline's lash and play because of that.

How much play is to much? I believe mine does have quit a bit of play if I remember correctly from the clutch job. I have a torsen 4.30 rear differential if that matters any. Is there a fix or rebuild for this problem with the differential or just replace and hope the new one is good? I really don't want to replace the differential unless I have to. But I don't want to put money into parts that aren't required.

Good question, and I don't know. I usually listen for the lash. If a diff is heading south, the lash noise while driving is so loud it sounds like driving next to a diesel train at speed, then BOOM. The problem I have had is a lot of shops don't know how to rebuild a diff, particularly setting the lash. It's not cheap. Was your diff dampener still attached? It looks a bit like a Maltese Cross rearward of the input flange (where the driveshaft attaches), and I have seen one the came loose and was banging around on there.

Yes the dampener was still attached and seemed to be tight as it was in my way while removing the drive shaft. A pain to get tools in there. I believe my diff does make a little bit of a whining noise while cruising on the highway. I don't notice the noise much under acceleration but only at the position where theres only a small amount of throttle being applied. That's the only time I hear it anyways. Its made that noise since I've had it 25k ish miles so I'm not 100 percent sure its the diff.

It also seems to get much worse as the cars hotter. after driving for an hour on the way to work I will notice it sometimes.

I notice that on mine too. The car was down for about a year, though, so I don't know if I'm just hyper sensitive or something else. I have a 4.1 torsen in my '92 I pulled from a wrecked car. I am monitoring it, but hasn't become an issue yet. I am suspecting the driveshaft or diff bearings on mine. When my 1.6 pumpkin went, it was because the driveshaft became stiff/notchy and was sending a lot of vibration through the ring and pinion. I noticed when I would freewheel sitting at a stop I could feel the drive line bind up a little as the car slowly rolled backwards. When it was on it's death bed, it howled like a diesel train, then the pinion gear split lengthwise and broke a pie-shaped chunk out of it, thus ending the lesson.

There is no fix. It is common slop or free play in the ring and pinion of the diff and trans gears. The original post car is still running and driving with no issues to this day. The following things were swapped and never changed the noise. A turbo was also added and have not had any drive train issues.

Items Changed: Engine mounts, Clutch, flywheel, transmission, driveshaft, differential, diff bushings, and wheel bearings.

My goodness thank you for replying to your own post about this. Sounds the same as the ‘cluck’ sound that’s been driving me nuts since getting my NA 4 years ago.