I've had an occasional knocking sound from the rear of my 2.0 Z3 since I got it 4 years ago. I've changed the shocks, springs, top mounts, anti roll bushes, tank straps and even the beam bushes but it's still there. It's not a major problem but it would be nice to find the source. I eventually decided it must be a worn-out driveshaft centre bearing, so got the car off the ground and removed the exhaust to get access only to find the bearing looks to be in perfect condition. My question is.......should I just replace the bearing anyway seeing as I've gone to so much trouble to access it or should I just leave it alone and simply change the guibo as it's definitely seen better days and I wouldn't have to take the driveshaft off the car. The replacement bearing would be Febi brand and probably not near the quality of the BMW one that's on the car. I'm not in any hurry to get the car back on the road but in two minds at the moment as to how I should proceed and would welcome any thoughts. Thanks
Z3 Driveshaft Centre Bearing
- Thread starter Andy 4D
- Start date
- Joined
- Feb 18, 2016
- Points
- 231
- Model of Z
- Z3M Imola and Z4 (e89)
If there is no physical play in the bearing its unlikely its causing a clunk, it would whine if worn, that said strange things can happen when a load is put through the drive train. Just a thought but I would take a look at the diff, get the wheels off the ground and get someone to turn the prop back and fore and listen at the diff for clunking, it's not uncommon.
Thanks, was planning to try that while I’m at it. There’s a good YouTube video from a Belgian guy with a Z3 coupe that shows various test that can be done. As for the centre bearing, as there seems to be no obvious fault with it, do you think I should just leave it alone?
Sometimes a clunk from the back can be as simple as an exhaust support bracket.
Have you checked the condition of the rear drop links and the security of the bracket that bolts direct to the trailing arm. Just a small gap can cause a clunk if not 100% tight. Also check the condition of the bushing for the differential, and if its been changed that its been orientated correctly when fitted.
Thanks, have already replaced the drop links and the diff bushing looks ok.....but you never know!! I seem to remember someone saying on here they had a clunk and it was the float in the fuel tank. The car is nearly 1/4 of a century old so I guess you have to expect a few noises, just frustrating when you can't pin it down.
Many moons ago I had a late 70s fiat 124 Spider. First convertible and loved it.
Over a year I had a clunking that started and slowly got worse. It only happened in 1st then second when starting out.
Turned out to be the center bearing getting worse. Under load it would throw the shaft out of whack so it would vibrate the mounting flange.
Took quite awhile to find it but soon as it was replaced the shaft ran smooth and all the noise was gone.
Over a year I had a clunking that started and slowly got worse. It only happened in 1st then second when starting out.
Turned out to be the center bearing getting worse. Under load it would throw the shaft out of whack so it would vibrate the mounting flange.
Took quite awhile to find it but soon as it was replaced the shaft ran smooth and all the noise was gone.