Rubbing/grinding while turning tightly.

[JFB]

My car was parked for the winter. I took it out early March and replaced my 220s with AG 359s with a slightly more aggressive offset.

I started noticing that when I turn tightly at slow speed (like in a parking lot) I get a rubbing or muffled grinding noise seemingly coming from the rear of the car. It seems to be happening on both left and right turns. The weird thing is I try to repeat the noise after I have just heard it by completing the same turn, but the noise isn't there anymore, making it very difficult to duplicate the problem. Mind you, the noise keeps happening randomly,yet on a daily basis.

That noise wasn't there last year.

Before I bring it in, id really like to have an idea of what the problem could be, and furthermore, be able to replicate the issue...

Could it have anything to do with the new offset wheels? I wouldn't think so, because we're talking about less that 10mm either side, but it's the only real change between last year and this year....

Thoughts are most welcome.

Thanks

[Properstyle]

have you recently changed your diff fluid?

[JFB]

I had it changed early last year by the dealer. But later in the year, the drive shaft differential seal was replaced due to a small leak. I assume they refilled the diff after the repair. There was no noise after the fix that I can remember.

My first thought was diff fluid, but with what I just wrote above, plus the fact I can't immediately duplicate the problem, it made me wonder if it could be something else.

[gfisher99]

If there is no physical rubbing from the new tires (inspect for rub marks), it's likely the differential. The noise is normal, but if you do not like it, you can have an additive put in there that will make it go away. It decreases the friction in the LSD.

[kb9uwu]

probably full loss/total..

[IIAp3x]

I would not suspect the 359's to rub in the rear... Mine don't rub in the rear and I have spacers in the front... Probably time to do a diff fluid change to the special BMW formula or redline's formula...

[TWiTCHY]

OP what size tires are you running?

[JFB]

OEM size... 265/35ZR19. Michelin PSS

[kb9uwu]

searching "turning rubbing" resulted in 3,950 posts on m3posts, btw.

[JFB]

Originally Posted by kb9uwu

searching "turning rubbing" resulted in 3,950 posts on m3posts, btw.

Appreciate that, but the forum search function on my app hasn't worked in months...

[TWiTCHY]

Originally Posted by JFB

OEM size... 265/35ZR19. Michelin PSS

That's for the rear? If you are running 265/35 up front with the AGs you might rub. Not sure why you'd hear it from the rear though. Can you have someone drive the car for you while you follow and listen?

[JFB]

Originally Posted by TWiTCHY

That's for the rear? If you are running 265/35 up front with the AGs you might rub. Not sure why you'd hear it from the rear though. Can you have someone drive the car for you while you follow and listen?

Yes, in the rear... Fronts are 245.

I'll try and listen from the outside, that's a good idea.

[Helmsman]

The diff grind in a way I don't think you'd confuse with tire rubbing. Mine grind a tad every morning first turns just to go away after started to warm up. Makes me feel good as I know it works (changes fluid 14month ago).

Grind continue also after car warmed up?

[tropicatango]

Finally, did you find out where this noise was coming from ?

[JFB]

It's still there. I'm assuming it's the differential as everyone points out...

I hear it once in a while, nothing seems broken on the car...

[Tewie]

Records from the previous owner of my car show the same symptoms. BMW replaced diff fluid of a different viscosity and solved the problem.

[kb9uwu]

Originally Posted by Tewie

Records from the previous owner of my car show the same symptoms. BMW replaced diff fluid of a different viscosity and solved the problem.

They added a friction modifier, which negates the limited slip part of the differential.

[Bimmer22]

BMW Service bulletin: SI B33 01 02
http://www.m3post.com/forums/attachm...2&d=1322027419