Diff Clunk

[Etansinsta]

Not too sure where to start looking for the root but anyways;

2010 e92 m3 6mt

Picked it up and it has an audible clunk in the back end. Drove it around and everything works fine, clutch holds strong etc.

Now the previous owner advised that he took out the oem diff and had a shop install the turner diff and turner solid diff bushings.

Prior to the turner diff and bushing install, the car allegedly had no clunk.

Immediately following the turner diff and solid diff bushings install, the car clunked quite bad.

The owner then returned to the shop and had the turner diff removed and a brand new oem diff installed.

The turner solid diff bushings were left installed with the oem diff.

The clunk is audible when letting the clutch out in first from a stop and when shifting to reverse.

Sometimes the sound can be heard going over bumps I believe, or that could be a coincidence based on my foot movements.

The clunk is also audible changing from 2nd to 3rd gear.

It does appear as the though the car has new cvs which were installed at the same time as the new diff.

I'm not sure what to check next. I've had the back wheels in the air and idled it while shifting to 1st and reverse. The noise is coming from inside the diff it appears but I can't see anything wrong as the oem diff only has approximately 4500 miles on it.

Any advice is much appreciated

[FazerBoy]

I think that is quite normal with solid diff bushings. It’s the price you pay for increased performance.

I’ve had those bushings in my 6MT now for 20,000 miles and the car drives fine, but I do get that clunking at slow speeds.

[pbonsalb]

You have much less isolation so you will hear more driveline clunks.

[Etansinsta]

Originally Posted by FazerBoy

I think that is quite normal with solid diff bushings. It’s the price you pay for increased performance.

I’ve had those bushings in my 6MT now for 20,000 miles and the car drives fine, but I do get that clunking at slow speeds.

Originally Posted by FazerBoy

I think that is quite normal with solid diff bushings. It's the price you pay for increased performance.

I've had those bushings in my 6MT now for 20,000 miles and the car drives fine, but I do get that clunking at slow speeds.

I will definitely be removing them and replacing with stock.

I read somewhere else on here people were commenting that their driveshafts required replacement and that is what is causing the clunking but I guess it's something to sort out after the bushings if the noise is still present.

[Etansinsta]

Originally Posted by username69

I will definitely be removing them and replacing with stock.

I read somewhere else on here people were commenting that their driveshafts required replacement and that is what is causing the clunking but I guess it's something to sort out after the bushings if the noise is still present.

Figured I would update this for anyone with the same issue.

I left the solid diff bushings in and replaced the driveshaft entirely, including the centre bearing and it SOLVED the issue entirely.

I have read of other people replacing only the centre bearing and it fixed the issue, and I've also heard people have simply added more grease to the centre bearing to solve the issue.

[Redd]

How bad is the diff whine with solid diff bushings? Do you daily the car?

[Etansinsta]

Originally Posted by Redd

How bad is the diff whine with solid diff bushings? Do you daily the car?

I've since sold and replaced with a dct model but it was barely noticeable during daily driving.

With stock exhaust it was very easy to tune out. Most noticeable at hwy speeds when you give it some gas.

To be fair I also didn't notice a difference having them over the stock bushings

[JetBlack_M3]

My diff. started clunking bad due to installing solid bushings. It was completely fine prior to installing the solid mounts. Im replacing the diff. and going back to oem bushings. The clunks at slow speeds is nerve wrecking

[amrazM]

Originally Posted by boussi33

My diff. started clunking bad due to installing solid bushings. It was completely fine prior to installing the solid mounts. Im replacing the diff. and going back to oem bushings. The clunks at slow speeds is nerve wrecking

I really wonder why so many people install solid diff bushings, its literally mindblowing why people do that on a straight up street driven car.....


then complain about it.

[JetBlack_M3]

Originally Posted by amrazM

I really wonder why so many people install solid diff bushings, its literally mindblowing why people do that on a straight up street driven car.....


then complain about it.

I mainly installed them because I was getting wheel hop with my rubber mounts. I didn't wanna risk breaking anything. I was aware solid mounts with cause nvh and I'm not concerned about that. But we're they the cause for my differential clunking is the question