Rough sound from rear during sharp low speed turns...

[thai357sig]

I remember it happening a few times last fall prior to me changing from PS2s (summer) to Contis DWS (winter). Well I've changed back and it sounds even rougher than what I have remembered. This is on stock 18" wheels. It only happened when the tires were worn to about 5/32" or less. Those PS2s from last fall are gone when replaced with Contis, the rubbing noise is now occuring with a second set I bought from a forum member. The rears have 4/32" rubber left. I don't remember it happening to the Conti which is brand new.

[SlamMan]

Does it sound like the tire rubbing on the fender liner? Mine was doing that and it was fixed under a service bulletin. They basically just changed the diff fluid. Seems to have taken care of 95% of the issue.

[mot]

Originally Posted by SlamMan

Does it sound like the tire rubbing on the fender liner? Mine was doing that and it was fixed under a service bulletin. They basically just changed the diff fluid. Seems to have taken care of 95% of the issue.

^^this

[GreasyGinzo]

Originally Posted by SlamMan

Does it sound like the tire rubbing on the fender liner? Mine was doing that and it was fixed under a service bulletin. They basically just changed the diff fluid. Seems to have taken care of 95% of the issue.

Is there a link to this SB on line? I would like to more about this...specifically if the new fluid increases or decreases lock up.

[-=Hot|Ice=-]

Diff fluid needs to be changed.

[thai357sig]

Thanks, guys. Just made an appointment. I told them my my rear differential is noisy when making sharp low speed turns, to replace diff fluids. If they give me any lip I'll just have to pull a Chuck Norris on 'em and throw a Roundhouse to the head.

[Empower3d]

My car has a thumping sound from the passenger rear tire area only when I take sharp right hand turns. I dunno if this is the same problem... Its not a grinding sound as people have previously posted. Anyone heard of this?

[BMW2002tii]

just bought from the dealer the new diff. oil yesterday ($45 each) and you need 3 of this.
im planning to make the change myself this weekend...
wish me good luck....i hoppe this solve the problem.

[M3LISSA]

its so stupid, but it seems almost everyone gets this stupid sound. It all ends up being the same thing, so why dont they just put the right fluid in it in the first place? It would save everyone alot of time.

[Silverstone]

Had the same thing...Changed the Diff. Fluid sorted it out instantly.

[thai357sig]

Finally took my car in last night at 6:00pm for rear differential grinding noise. Made the appointment in the morning, they offer free loaners, usually through Enterprise. They also have dealer BMW loaners, but not many and it's first come first serve and no reservations. Well, I knew Enterprise closes at six and most people return loaners and pick up their vehicles after work, so now employing this tactic they always find me a BMW loaner when I go in for service. Got the new 2011 535i. It has decent power but man is it a boat! I had originally wanted the 550i but decided for the M3 at the time because the model is only six months old versus 7 years the the 2009 550i. Without electronic dampening this car floats too much. I guess I'm spoiled with the M division.

Anyways, I have driven my car with at least a year with this noise thinking it was a simple tire rubbing issues. Do you guys think I've done irreparable harm to my rear diff after driving so long with the oil needing service?

[jeff4598]

Changing the fluid is only half the fix- see the TSB! It has to be driven in circles in a certain way.

[NYCM3ryder]

yea its the diff fluid.. had it changed now it does it once in a blue not like before..

[thai357sig]

So left my car over night and got a call at 11:00am to pick up anytime. That was a quick turn around! They changed the diff fluid to a heavier one, no other issues. The must of drove in circles for an hour cause the put six miles on my car!

[Radiation Joe]

Originally Posted by melimel

its so stupid, but it seems almost everyone gets this stupid sound. It all ends up being the same thing, so why dont they just put the right fluid in it in the first place? It would save everyone alot of time.

Thanks, Mr. clueless.

The reason many of us live with the sound is that we want our limited slip differentials to remain limited slip. The replacement fluid is more slippery which make the LSD less effective. We, and the engineers that designed the car want it to drive like a performance car. That's why we keep the original fluid.

If noise is more important to you than performance, maybe a Lexus should be in your future.