2000 z3 driveline/transmission noise after CSB replacement.

[Chillard1]

I recently bought a 2000 z3 2.8 with 120,000 miles and 5spd. I could tell there there were some worn driveline components due to clunking and bouncy acceleration due to a toasted giubo. So i went through and replaced the giubo, center bearing, and the rear differential bushing as well to cover my bases. After this work I now get a whistling sound that starts at around 35-40 mph. At first i thought it was simply wind due to a misfitted heat shield or something. But the sound changes pitch when i engage and disengage the clutch. Additionally, while trying to diagnose i noticed a very faint rubbing/scraping sound that can be heard inside the car only with the car in nuetral and the clutch completely let out (foot not on the clutch) when sitting still, I’m pretty sure this was not present before the job and it may be present when moving but it just drowned out by other noises. I’m going to go back in and recheck all the driveline components but to me it seems like a transmission deal. So i wanted to ask if this sticks out anyone, or if theres any way I could have damaged the transmission when taking the driveshaft out and putting it back in. I supported it the whole time the trans cross member was removed...thanks in advance.

[Muzz258]

Did you fit rubber or poly bushings on the diff? Poly will transmit more noise.

Did you mark the position of the drive shaft then taking it apart at the diff, transmission and center bearing locations? This is to ensure that the drive shaft is assembled correctly to stop any vibrations.

It almost sounds like a throw out bearing issue in the clutch (wild guess).

[solimans]

The CSB requires forward preload when installing. Also the noise could be the heat shield hitting the driveshaft. More wild guesses


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[Chillard1]

Thanks for yalls replies. I did mark the driveshaft and preloaded the csb forward about four millimeters. Here are a couple videos of the noise: one while driving and one in a parking lot idling.

https://youtu.be/w3Zgykf6msE
https://youtu.be/yq1ITu4tHXM

[Chillard1]

Went OEM on the bushing

[ThatZ3Guy]

Thanks for yalls replies. I did mark the driveshaft and preloaded the csb forward about four millimeters. Here are a couple videos of the noise: one while driving and one in a parking lot idling.

https://youtu.be/w3Zgykf6msE
https://youtu.be/yq1ITu4tHXM

I have no advice to offer, but I'll bump your thread because that noise is awful!

[WMBpilot]

I just had my csb and flex disc replaced on my 1.9l and it makes the same noise. This was the second one that did this. They too were oem. I’m wondering if there is a bad batch of csb’s out there.

[Chillard1]

Did just popping a new csb in fix the issue or are you still chasing the problem? I guess its possible the new csbs are bad. I was thinking more along the lines of the new flex disc and diff bushing taking up slack that is now making the cv joints on the axles upset. Regardless, you’re this first person I’ve found that recognizes this noise so any insight you have is great.

[s8ilver]

I did a driveshaft replacement fairly recently (to eliminate the famous clunk). The company that rebuilds the shafts also installs a new CSB. I'll inquire with them if they use OEM or not. Quality seems excellent, and I have no noise.

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[WMBpilot]

I’ll be taking mine back to the shop next week. I’ll let you know the results.

[rf900rkw]

Noise 1, I don't hear anything unusual.


Noise 2 is the rubber dragging on the dust shield. I've seen bearings put in backwards. I've seen the dust shields bent by changing the bearing with a claw hammer rather than the proper puller and press/driver.

[Chillard1]

Are the dust shields the bronze colored washer like pieces that are on each side of the bearing? This sounds very plausible as I bent one up pretty bad getting the old bearing off. I had thought I flattened it out and made sure the bearing wasn’t rubbing but this is definitely something I will re check.

[rf900rkw]

https://www.realoem.com/bmw/enUS/sho...diagId=26_0105


10 and 13.

[Chillard1]

I’m thinking you nailed it, will report back.

[Chillard1]

Unfortunately this did not solve the problem...I have removed the dust shields completely. I have also run the car on jack stands with the heat shields and exhaust removed and the noise is the same. Pretty stumped, I think my next play with either be a shop to diagnose or changing the tranny and diff fluid (not at the same time) to see if this changes the noise at all.

[rf900rkw]

Argghhh. I'm pretty positive that is a rubber on steel. noise. I will say if it is the trans or diff, changing the fluid will be futile. It would take a major failure to make that much noise.