clacking sound coming out of driveshaft

[trashcop 80s 80s]

If I let out my clutch hard while cruising I will get a metal type clacking sound coming from the rear of the car. I put my car on a lift and looked around and didn't seem to notice too much slop in the system, but then I bumped on the driveshaft and I can hear a metal clack sound coming from inside the rear section.

Is it possible for something to break inside the rear shaft. I had someone listen while I was in the car on the lift, I was letting the clutch out hard in first. He confirmed the the noise was coming out of the rear section.

What's going on here? I don't really think it is the u joints or CSB, it really sounded like the clacking was coming out of the driveshaft.

[trashcop 80s 80s]

any ideas?

[trashcop 80s 80s]

See if this helps any. When I am cruising, and I hold the clutch in, and then do a decently hard shift from 3rd to 4th or so. I get the clacking sound coming from the rear. Any help?

[dirty30]

Remove your exhaust heat shielding and check the area where the driveshaft centersupport bearing is, I just had this similiar sound coming from my driveshaft area, visually there is nothing wrong yet I found that my center support bearing was so dead that the driveshaft was dragging on the heat shield. So I pulled a r3v and just beat a dent in the heat shield so it would clear....HAHAHAHAHAHA

Hope this helps...good luck

[Old'n'Slow]

any ideas?

Mine does this as well, despite a new driveshaft, new clutch, upgraded differential, new CSB, new guibo, etc...

Personally, I think it's gear lash inside the tranny. The sound gets conducted down the driveline and is transmitted to the body at the rear subframe mounts. Mine is especially loud because of the urethane subframe mounts that make the car corner like crazy, but transmit every little sound...

When I had the tranny out I could hold the input shaft and rotate the output shaft several degrees before I felt anything at the input shaft. Shifts fine and isn't noisy, other than this. I also hear a sound during shifts, so I think it's a sign of lots of miles. In my case, 210,000 miles on the original tranny...

I wouldn't worry unless it gets worse...

[Sean]

Mine does this as well, despite a new driveshaft, new clutch, upgraded differential, new CSB, new guibo, etc...

Personally, I think it's gear lash inside the tranny. The sound gets conducted down the driveline and is transmitted to the body at the rear subframe mounts. Mine is especially loud because of the urethane subframe mounts that make the car corner like crazy, but transmit every little sound...

When I had the tranny out I could hold the input shaft and rotate the output shaft several degrees before I felt anything at the input shaft. Shifts fine and isn't noisy, other than this. I also hear a sound during shifts, so I think it's a sign of lots of miles. In my case, 210,000 miles on the original tranny...

I wouldn't worry unless it gets worse...

Seconded. ;)

[mjvela]

trashcop,
did you figure out what was going on with the driveshaft?
I just replaced my driveshaft and csb and I have the same issues going on.

Remove your exhaust heat shielding and check the area where the driveshaft centersupport bearing is, I just had this similiar sound coming from my driveshaft area, visually there is nothing wrong yet I found that my center support bearing was so dead that the driveshaft was dragging on the heat shield. So I pulled a r3v and just beat a dent in the heat shield so it would clear....HAHAHAHAHAHA
Hope this helps...good luck

I don't even have my heatshields on and I still get the clacking.

[ZiMMie]

Chk the fluid Level in the tranny as well.

[sakdbma]

Old thread i know, but i have just finished doing a disc brake rear conversion on my 320i, did all the bushings with I.E Urethane and upgraded to a 3.64 medium case diff.

When i flushed the diff i replaced the oil with SAE 90 LSD Valvoline Oil. Is this to thin for Non LSD? Im getting a scrolling/groaning sound from the diff at low speed and the scrolling get faster and less noticable as i gain speed, also does it on hard cornering.

I have also got the above described noise of the 'clanking' when hard shifting down or changing reverse to drive or drive to reverse. It doesnt sound to good, everything is bolted up tight and i cant see any tell tale signs of where or why i am getting these noises.

Any ideas??


TIA

Chris

[trashcop 80s 80s]

I'm pretty sure 80-90 viscosity is ok. Does it get louder on hard cornering or is it the same. Check your center support bearing. If it is bad the bearing could make some noise. Also check your rear wheel bearings and see if they have excess play and noise.

The clacking noise was my rear ujoint in the driveshaft. It was frozen completely and would only flex in one direction. I replaced that and it helped, but their is still some noise. I think it might be my rear diff mount. Also check the four big top bolts holding on your differential.