BMW M5 Forum and M6 Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
51 Posts
Discussion Starter #1
My Indy shop is saying that I may need a whole new transmission... HOLY #$^* !!! Nobody in town is willing or capable of tearing apart the tranny to see what the problem is.

I'll definitely take it for a second opinion.

What would you guys do... keep driving till you actually get a "control message" or till it really degrades ?

My indy shop is great... really good guys, but they don't have very much experience with the M's. My only option in town is to go to the stealer?

What do you guys think?

Heres some info from a previous post...exactly whats going on with my car:

06, 104,000kms, SMG, minor mods - afe intake, wheels and tires.
I replaced the clutch/flywheel and other tid bits last year (bimmerzone clutch package). Had the 100,000km service done at BMW in Oct. and just had a few of the ignition coils replaced after a CEL came on. Car had been running great... still is, just now with a noise.

The noise is a bit hard to explain but it sounds something like a supercharger belt noise. A high pitch mechanical/belt like noise... it vary's in pitch with engine speed... more rev's, higher pitch... less rev's, lower pitch.

I hear it the most when the car is on the cool side and I am in gear and coasting. As soon as i get on the gas the sound disappears. It seems like it happens most when in 1st, 2nd, and 3rd... although the wind noise could just be hiding it when i'm in 4th or higher.
The car drives fine.. no loss in power, no CEL's, nothing... just a belt like, bearing like, supercharger like, noise while in gear and coasting. No noise when in neutral and coasting, no noise when on the gas accelerating. When the car is fully up to temperature the noise isn't as loud, and sometimes not there at all.

Its a bit tough to tell where the noise is coming from because it can't be reproduced in the garage with the hood up and me crawling around.

I'm at a loss... i don't know if maybe the clutch needs a re-adaptation or it has something to do with the diff ???? noise wasn't there one day... was the next and the only thing I did in-between was wash the car, and go for a bit of a spirited drive...which may have included some "DSC Off" time ;-)

I hope one of you out there has had this and can gimme some leads... the only things i found in a search had to do with a noise from a power steering system (which i checked and topped up the fluid) and the possibility it might have something to do with the A/C, which i tried to trouble shoot (driving with it on and off, high/ low fan) with no success.

I replaced the idler and tensioner pulleys as well.

Heres a youtube link to hear what it sounds like:

https://www.youtube.com/watch?v=V2prwKjDkCk

I really need some help here

So... What do you think ?????
 

·
Registered
Joined
·
5,673 Posts
I could be mistaken, but the last few seconds of that clip, it sounds as if the noise is gradually decreasing while the tach shows a rise in RPM. That sort of decouples the noise from engine RPM, but not from the transmission layshaft.

It really sounds like a diff to me, but it's hard to tell from a video. Can you have someone in the back seat listen out the window?

A diff under load (accelerating) will thrust the pinion one way against the bearing and less off load. Could be coming from the diff for sure.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #3
Ran it cold on the hoist... had all the belly pan's off and its definitely coming from the transmission... somewhere in the middle to back of the tranny. A bearing is coming undone.

Can you get inside the tranny... can they be rebuilt or do I have to buy another one?

Does the tranny share the same oil at the hydraulic pump?
 

·
Registered
Joined
·
5,673 Posts
Ran it cold on the hoist... had all the belly pan's off and its definitely coming from the transmission... somewhere in the middle to back of the tranny. A bearing is coming undone.

Can you get inside the tranny... can they be rebuilt or do I have to buy another one?

Does the tranny share the same oil at the hydraulic pump?
They can be, but not by any dealership or indy. Mostly transmission repair shops. Just pull the SMG actuator and pump off first and send it to any shop that rebuilds Porsche, BMW, Ferrari, etc manuals and it's straightforward from there. A couple of members on the forum here have done it, but not for the faint of heart.

The cost however will probably be as much if not more than a used transmission with low miles.

The lubricating oil is different from the hydraulic fluid. I would ask them to do a fluid change first and see if that helps. Not likely, but cheaper than a transmission.
 
1 - 4 of 4 Posts
Top