need some help diagnosing plz

[GewoW]

hey all, so recently my car has been making a funny rubbing type sound that i can feel in the car. originally i thought it was coming from the front, but now i believe it is coming from the middle/rear. It only occurs when turning, and NOT full lock. about 1/2 way and more when turning right than left. it sounds like a rubbing sound and occasionally results in minute speed changes. it is also much more noticeable when going very slowly.

i just recently put on my winters with a 12mm spacer in the front. the sound did not start after that. it started after I had bmw change 2 of my tires (left - p.s. tires are within a few hundred km of each other, they are not mismatched), so i thought maybe it's something they did.

so since originally i thought it was coming from the front I :

-raised each front corner, freely spun wheels, sound good

-took each front tire off, spun just the rotor and looked both sides, good. no hanging detached plastic anywhere in the wheel well

-measured each front rotor (I have AP kit), maximum wear is 0.5mm on front left, which is <2mm recommended replacement

-retorqued all wheels, good

-drove around, still making the sound

-had a friend of mine sit in car with me and he brought up the idea that it's coming from the rear and after careful listening, i am of this opinion

-he thinks its the diff....which would fit with why this happens when car is turning and why its coming from rear. it makes sense. i agree

any opinions before i go to BMW?

thx all for your help


****check posts 11 and 12 for updates

[CanAutM3]

What size of tire tire are you using in front?

I get light rubbing in the right wheel well with partial lock when turning right. I also have 12mm spacers in front. The spacers increase the arc traveled by the wheel when giving steering lock. In the back of the right wheel well, there is a protrusion in the fender liner, this where I get the rub.

[arter]

Could try removing the spacers to see if BMW messed them up ( quick cheap check due to the timing).

[GewoW]

these are both non-contributing factors. checked both. and my tires also dont rub at full lock and this occurs about 1/2-3/4 the way to full lock, not at full lock

thx tho

[CanAutM3]

Originally Posted by GewoW

these are both non-contributing factors. checked both. and my tires also dont rub at full lock and this occurs about 1/2-3/4 the way to full lock, not at full lock

thx tho

I am not getting rub at full lock either, only partial lock.

But if you checked for rubs and did not see any, it obviously isn't your problem .

[GewoW]

Originally Posted by CanAutM3

I am not getting rub at full lock either, only partial lock.

But if you checked for rubs and did not see any, it obviously isn't your problem .

interesting. tires are 245/40/18 with stock 8.5s with 12mm spacers. i will check as someone is turning the steering wheel...i did not check every single angle

thx for suggestion

[Rshane]

Well, if the only thing you changed was your wheels/tires before the noise started, it is likely the cause for the noise. By raising the car and spinning the tires you are taking the weight off the suspension. So the wheels hang lower and would give you more clearance so, there would be no rubbing.

I would check the inner fender liner and look for signs of rubbing. Also, try removing the spacers and see if it goes away. If all else fails you should take the car to the dealer and see what they find.

Good luck.

[AshyLarryMP]

I believe your problem is rear differential clutches binding. I was experiencing a rubbing noise while turning at slow speeds. Dealer replaced clutches at 15k miles and no more noise.

[GewoW]

Originally Posted by AshyLarryMP

I believe your problem is rear differential clutches binding. I was experiencing a rubbing noise while turning at slow speeds. Dealer replaced clutches at 15k miles and no more noise.

this is my thought, thanks

i will ensure no rubbing at all angles and if not, then will bring to dealer as i think this is likely it

[bsiciliano]

There's a service bulletin on the diff issue. Search for it. It's a simple diff fluid swap at the dealer.

[GewoW]

*update*

so i checked if there is any rubbing with wheels mounted and weight on suspension

here are pics:

Left tire turning left




Right tire turning right - less space than the other side...maybe correlating with the increased sound I am hearing when turning right?





Do you think this is the problem? It seems like it would be to me. Also, can I keep running these tires? I am running 12mm spacer, without which I cannot clear brakes. They are completely new. I don't want to spend on 2 new front tires. Next change I will downsize to 235 fronts (245 now). never had this issue with the vredesteins wintrac though...maybe they were made narrow? These are Dunlop 3ds

[GewoW]

*update2*

So i don't think its the tires....I have applied some painters tape on the part with closest proximity to the tires, bilaterally. Drove around, made sure i heard the sound. Then checked them. Clear:

LEFT



RIGHT (side where tire is closest)

[rawedge2]

You need to have the Diff Fluid Service Bulletin Performed as stated above.

---

I went through a similar situation after installing Springs/spacers thinking i was rubbing. I switch spacers, then realized it wasnt that and had the e-brake cable looked at thinking that could be getting caught up some how..

The way you describe it is spot on. It would sound like a moan, it would slow the cars speed when it occurs, Happenening at low speeds in a turn without the wheel at full lock..

Also it would be more prevelant while the diff fluid is cold.

Get the bulletin done, give it a few miles to work throughout the diff and you should be all fixed.

[GewoW]

will b going today. thx

here is the full service bulletin for anyone's interest:

SI B33 01 02
Rear Axle January 2009
Technical Service

This Service Information bulletin supersedes SI B33 01 02 dated March 2008.

designates changes to this revision

SUBJECT
Grinding Noise from the Differential during Slow Cornering


MODEL
E46 M3 from start of production

E60 M5 from start of production

E63, E64 M6 from start of production

E90, E92 and E93 M3 from start of production

E85, E86 with S54 from start of production


SITUATION
A grinding noise may be heard coming from the differential during slow cornering.

This noise is best heard during tight cornering situations; for example, while parallel parking, driving in a tight circle, etc.

CAUSE
When the rear wheel speed differential varies during tight cornering, a slip stick effect is created on the lining and steel discs incorporated in the differential locking clutch, causing the grinding noise.

This noise typically goes away as the locking clutch discs in the differential are broken in.

The break-in time varies depending on driving habits; for example, tighter cornering (working the locking clutch) means that it takes less time to break in the locking clutch discs.

CORRECTION
If a customer complaint is verified as described above on the E46 M3; E60 M5; E63 and E64 M6; or on the E90, E92 and E93 M3 vehicles, the differential oil should be replaced with a specially formulated differential oil, BMW part number 83 22 2 282 583.

PROCEDURE

Drain the differential oil. Refer to the appropriate model repair instruction in TIS:

Main Group 33 / Subgroup 10 / RA 0011259.

Refill the differential with special differential oil as shown in the illustration below.

Differential fill capacity = 1.2 liters (1.3 quarts).


Remove the seal (1) between the bottle cap and neck.

Pull the filler tube (2) out of the bottle.

Remove the cap (3) from the filler tube (2).

Insert the filler tube into the fill hole in the differential and with the bottle positioned under the output shaft, squeeze the bottle to transfer the oil into the differential.

Road test the vehicle.

With the vehicle at operating temperature, drive in tight circles (20 circles in each direction), allowing the special oil to coat the locking clutch discs.

The grinding noise will decrease when the locking clutch discs are sufficiently coated. Some slight noises may still be heard after driving in tight circles. Advise the customer that it will be necessary to drive the vehicle up to 600 miles before all noises are eliminated.

Note: Vehicles that have had the differential oil converted to this special oil should continue to use this oil whenever a service requiring the differential oil replacement is indicated.

PARTS INFORMATION
Part Number
Description
Qty.

83 22 2 282 583
Special differential oil kit
1

Contains 3 bottles - .5 liters (.53 quarts) each

(order quantity 1 : bill out quantity 3)

WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.

Defect Code
33 10 92 39 00

Replace differential oil with special oil

Labor Operation:
00 53 267

Labor Allowance:
3 FRU

[GewoW]

was the diff oil. all fixed now

[M3PO]

They added a friction modifier to quiet the diff. It's my understanding that it slips the clutches more and locks up more slowly.

[sjl104]

I had the same problem, 'rubbing noises' from the back end when on a tight lock at low speed. First stance from the dealership was that a modified oil was only a requirement in earlier E46s, the 90 series was ok. A couple of weeks later they changed their tack and someone looked in the right book......oil was changed to Castrol Syntrax 75w 140. No problems since.....