S52/ZF320 Driveline Vibrations

[jbontke]

Typically when it is vibrating pressing the clutch causes them to immediately stop

What is your clutch, flywheel, throw-out bearing setup?

[cdl723]

Does depressing the clutch cause any change in the vibration?

Typically when it is vibrating pressing the clutch causes them to immediately stop

[jbontke]

Does depressing the clutch cause any change in the vibration?

[cdl723]

Is your exhaust snug?

I believe it is. I had the m3 exhaust poorly welded onto the e30 cat back to get the car moving. It did it when I had this exhaust and when I rebuilt the exhaust.

[jbontke]

Is your exhaust snug?

[cdl723]

Have you looked for any areas where the drive shaft could have possibly contacted the car? Can it be replicated with the car on jackstands?

I haven't been able to see any marks on the DS or in the trans tunnel. I was going to remove the heat shield and run it on jack stands to check for any weird vibrations or misalignments with the driveshaft.

[jbontke]

Have you looked for any areas where the drive shaft could have possibly contacted the car? Can it be replicated with the car on jackstands?

[cdl723]

https://www.youtube.com/watch?v=xg2RN5lhaqM

It sounds similar to this video at roughly 50 seconds, but a little deeper sounding and it keeps happening until i press the clutch in or start accelerating again.

[cdl723]

I am having bad driveline vibrations with an S52 swapped e30 on deceleration. I wish I had a video, but it sounds like the driveshaft or transmission is hitting the floorboard in a rhythmic fashion that is linked to the vehicle/engine speed. It does not happen while stationary. I can only replicate this when I accelerate, typically hard, then abruptly let off the throttle. To stop the vibration I usually speed up, slow down below ~30mph or press the clutch in. I have replaced just about everything in the driveline excluding the differential, engine and trans. The parts I have replaced in the last few months are as follows:
- Revshift 80a 24v swap mounts
- Garagistic 80a trans mounts
- New Meyle Guibo
- New aftermarket OEM replacement driveshaft with new CSB
- 3.07 LSD from e28
- 80a subframe, diff and trailing arm mounts
- stock untouched e30 axles and wheel bearings

I started the swap with the engine and trans mounts. I had a new CSB on the old driveshaft. The issue was observed before and after the replacement of the Guibo, driveshaft, and subframe mounts. Yes I have preloaded the CSB and installed the driveshaft per various manuals.

I called Revshift and they pointed to the trans mounts, so I decided to order new ones as I have been told a studded design is better than through bolt. They told me the trans mounts were roughly 1.3" and I measured the mounts to be roughly 1.25". I also noticed the driveshaft is pointed down in the CSB from the front of the car looking back.

This has been driving me crazy and I cannot figure out what the issue is