Found a driveshaft issue I wasn’t looking for!

[thatg]

So I recently swapped exhausts with the fellow M3 owner and put on the performance exhaust. After having it installed for a couple of weeks I noticed a metallic sound underneath the car when I would go into reverse and then fo so I recently swapped exhausts with the fellow M3 owner and put on the performance exhaust. After having it installed for a couple of weeks I noticed a metallic sound underneath the car when I would go into reverse and then forward. I assumed that maybe something came loose or wasn’t tightened properly during the swap so I stopped by the mechanic who did the install. He found everything to be tightened properly and noticed if you turn the rear wheel forward and backward you would hear the same metallic noise. After pulling down the heat shield it seems like the sound is coming from the driveshaft. He believes its a worn U-joint on the driveshaft.

I was wondering for the guys that have dealt with this issue before what route did you go? It looks like a new driveshaft from ecs or turner would be around $900. I’ve seen a couple of posters go with these guys
http://driveshaftspecialist.com/Import%20html/BMW.html

My mechanic also offered to remove my curren driveshaft and have it reconditioned.


This is the noise my car is making but not frequent currently. Only when backing up and then driving forward and occasionally over bumps.

[NoHedge]

Does your car emit that sound during hard acceleration? I've been hearing a metallic clink similar to that video, but with less volume/frequency. Trying to track down the cause has been a nightmare.

I've eliminated the differential as the clinking becomes more frequent after hard downshifts. I was hoping that it was related to the SIB about clinking during load transfer. Unfortunately, the noise still occurs when I hold onto the brakes and give it some gas (car is completely stationary). Given that the car is not moving, does the drivetrain transfer any load?

I suspect it's drivetrain related.

[LVI]

Bad driveshaft u joint. Rebuild yours with a new u joint and center support bearing. Make sure they rebalance it as well. A local driveline shop should be able to do if for $250-$350.

[RomanK]

Originally Posted by NoHedge

Unfortunately, the noise still occurs when I hold onto the brakes and give it some gas (car is completely stationary). Given that the car is not moving, does the drivetrain transfer any load?

I suspect it's drivetrain related.

Do you mean this?

[NoHedge]

Originally Posted by RomanK

Do you mean this?

Nope. Mine is more like flicking a glass bottle with your finger tips as described by a couple members.

I was thinking if there's no load transfer, then where is the sound coming from..

[thatg]

Originally Posted by NoHedge

Nope. Mine is more like flicking a glass bottle with your finger tips as described by a couple members.

I was thinking if there's no load transfer, then where is the sound coming from..

Yeah i liken the noise to bottles clanking together. When i forst started hearing the noise i thought i had forgotten some beers in the trunk or back seat. It was very hard to tell if the sound was coming from outside or inside the car. Its slightly more pronounced with the windows open.

$250-300 sounds reasonable, the car has 70k on it. Would it make more sense to pony up an extra $200 for a reconditioned(new?) driveshaft from the link i posted above?

At the moment i have nothing to compare to but the car does have a hard pullback when i left off the accelorator, wondering if this has something to do with that. My mechanic suggested the previous owner drove the car hard/shifted aggressively and thats what caused the u joint to go bad, don’t know if thats the case but the subframe bushings are worn as well. Im wondering what other wear and tear stuff i’d need to look for around 70k while im at it

[Solo_M_Tech]

Originally Posted by thatg

So I recently swapped exhausts with the fellow M3 owner and put on the performance exhaust. After having it installed for a couple of weeks I noticed a metallic sound underneath the car when I would go into reverse and then fo so I recently swapped exhausts with the fellow M3 owner and put on the performance exhaust. After having it installed for a couple of weeks I noticed a metallic sound underneath the car when I would go into reverse and then forward. I assumed that maybe something came loose or wasnÂ’t tightened properly during the swap so I stopped by the mechanic who did the install. He found everything to be tightened properly and noticed if you turn the rear wheel forward and backward you would hear the same metallic noise. After pulling down the heat shield it seems like the sound is coming from the driveshaft. He believes its a worn U-joint on the driveshaft.

I was wondering for the guys that have dealt with this issue before what route did you go? It looks like a new driveshaft from ecs or turner would be around $900. IÂ’ve seen a couple of posters go with these guys
http://driveshaftspecialist.com/Import html/BMW.html

My mechanic also offered to remove my curren driveshaft and have it reconditioned.


This is the noise my car is making but not frequent currently. Only when backing up and then driving forward and occasionally over bumps.

Its the ujoint in the driveshaft. Mine had made the same noise for over a year. It's survived 5 track days and a year of abuse making the noise. It will eventually break but I'm too lazy to change it now.

[M_GODZILLA]

https://www.ecstuning.com/b-turner-m...ission/665xkt/

this is what you need, all BMW has the driveshaft problem.
mine having the noise around 90xxx, dealer recommends replacing the whole driveshaft.

[LVI]

Originally Posted by thatg

Yeah i liken the noise to bottles clanking together. When i forst started hearing the noise i thought i had forgotten some beers in the trunk or back seat. It was very hard to tell if the sound was coming from outside or inside the car. Its slightly more pronounced with the windows open.

$250-300 sounds reasonable, the car has 70k on it. Would it make more sense to pony up an extra $200 for a reconditioned(new?) driveshaft from the link i posted above?

At the moment i have nothing to compare to but the car does have a hard pullback when i left off the accelorator, wondering if this has something to do with that. My mechanic suggested the previous owner drove the car hard/shifted aggressively and thats what caused the u joint to go bad, don’t know if thats the case but the subframe bushings are worn as well. Im wondering what other wear and tear stuff i’d need to look for around 70k while im at it

It's not worth spending anymore than it costs to rebuild the one you have. Buying one rebuilt will net the exact same result. There's nothing special about these shafts.

[NoHedge]

Originally Posted by Gears_and_Gasoline

Its the ujoint in the driveshaft. Mine had made the same noise for over a year. It's survived 5 track days and a year of abuse making the noise. It will eventually break but I'm too lazy to change it now.

What happens when the ujoint or related parts in the driveshaft fails? I'm guessing not catastrophic if you took her on the track

[LVI]

Originally Posted by NoHedge

What happens when the ujoint or related parts in the driveshaft fails? I'm guessing not catastrophic if you took her on the track

Your guess is very wrong. If the u joint snaps at speed you may be looking at a flinstone scenario ... It'll absolutely wreck the bottom of the car. Those catastrophic failures are fairly isolated but you definitely don't want to chance it, especially in a track environment.

[Loki Motorsports]

Has anyone ever converted to a 1-piece setup? Curious as to the costs associated with that.

[pbonsalb]

A bunch of us have one piece carbon fiber DS. MFactor sold them for a while but got in a legal dispute with the CF provider a while ago so those are NLA. Driveshaft Shop sells a CF one piece but it requires adapters at both ends and does away with the rubber coupler, which has caused vibration issues on some cars. $1500. If you wanted a steel DS, it would be less. Not sure there is space for an aluminum one piece, but don’t know.

[Loki Motorsports]

Originally Posted by pbonsalb

A bunch of us have one piece carbon fiber DS. MFactor sold them for a while but got in a legal dispute with the CF provider a while ago so those are NLA. Driveshaft Shop sells a CF one piece but it requires adapters at both ends and does away with the rubber coupler, which has caused vibration issues on some cars. $1500. If you wanted a steel DS, it would be less. Not sure there is space for an aluminum one piece, but don’t know.

Thanks for the reply. In a perfect world, I'd like to go with an aluminum one piece and keep the stock guibo for vibration dampening. Sounds like this would be a custom item however... Custom=expensive. lol