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BimmerWill
09-12-2012, 08:05 PM
So i've had a recurring problem with my inner sidewall wearing down and causing the tires to blow. From the looks of it the sidewall is rubbing the inner fender causing wear. There is a section on the sidewall that was sticking out a little more then the rest and had been rubbed clean of the protective coating that BMW put on from the factory showing bare metal. I beat that in today after losing another tire. My question is what is causing this. I crawled up in under the car tonight with a new tire mounted and examined the location of the tire in comparison to the inner fender well and the tire has a good inch and a half clearance to the fender well as well as being about an inch and half higher then the place that appears to be rubbing. So in order for this to be the cause the wheel would have to be shifting down and in at the same time in order to cause this rubbing. This is very puzzling because I cant understand how this would be possible. I also looked at the rear differential mount and from what i can tell appears to be cracked and may be bad allowing for the differential and axles to shift when going around a corner. However I would think that the independent suspension being mounted to the frame/body would prevent such an aggressive movement.

My question essentially is would the bushings for the differential or possible subframe failure cause this to happen. I had the subframe inspected about two years ago and they said it checked out but am unfamiliar with what parts are prone to break and cause this failure and where they are located. If anyone has any thoughts to this I would really appreciate it cause I am simply dumbfounded at the moment. :help
danewilson77
09-13-2012, 04:09 AM
My question essentially is would the bushings for the differential or possible subframe failure cause this to happen.

I had the subframe inspected about two years ago and they said it checked out but am unfamiliar with what parts are prone to break and cause this failure and where they are located.

If anyone has any thoughts to this I would really appreciate it cause I am simply dumbfounded at the moment. :help

How did the coil look while you were under there? How old are the shocks/dampners in the rear?

If the above check out ok....I would say, that you are correct in assuming, something in the subframe is destroyed and is allowing "too much play" in the rear drive train.

GoPro would be perfect for something like this. Mount under the car, in the subframe area.....then go for a drive. It would be easy to tell why the tire is rubbing.

If you don't have a GoPro........buy one, then do the repairs yourself. It would surely be less than goind to any shop.
gvcmel
09-13-2012, 04:40 AM
Assuming you are running ZHP stock rims?
danewilson77
09-13-2012, 05:04 AM
Assuming you are running ZHP stock rims?

Nope....he has Style 42, 16" rims. ET42....

http://www.zhpmafia.com/forums/showthread.php?7928-Spacers...

Moved to troubleshooting subforum.
BimmerWill
09-13-2012, 05:52 AM
Nope....he has Style 42, 16" rims. ET42....

http://www.zhpmafia.com/forums/showthread.php?7928-Spacers...

Moved to troubleshooting subforum.

They are the 17's

Gopro is a great idea I never would have thought of that thanks. I don't have one but some buddy's of mine do. Ill see if I can borrow one here in the next day or so. Not really sure where I should mount it though. Any suggestions?
Coils and shocks are fine I checked that side fairly recently actually so its not that.

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danewilson77
09-13-2012, 06:07 AM
I would mount it first in an area to get on video....the tire rub. Then...I would move it under the car, to view the subframe.

Get both on video as confirmation.

Maybe you can skip tire though, as you already have confirmation of that.:)
BimmerWill
09-13-2012, 06:25 AM
I would mount it first in an area to get on video....the tire rub. Then...I would move it under the car, to view the subframe.

Get both on video as confirmation.

Maybe you can skip tire though, as you already have confirmation of that.:)

Alright. Im trying to locate a camera now. Should be able to mount and test it by tonight

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Pip
09-13-2012, 07:01 AM
Great use of a gopro! Wouldn't have thought of this, but it will surely help figure things out and seems like a great idea for anyone wanting to figure things out that happen while driving.
BimmerWill
09-13-2012, 04:20 PM
Don't really have the cash for a gopro and im having trouble locating one. So im just gonna jack it up and take a look around. What are the weak points in the subframe that were prone to failure or was that mostly a problem in the front end and not the rear? Also from inspection of the bushings holding the sway bar on appear to still be sound. Are these the rtabs everyone refers to or is that something different?

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danewilson77
09-13-2012, 04:34 PM
http://video.google.com/videoplay?docid=8362789948066992482#

Bunch of pics here that you also may be looking for...

http://www.google.com/search?q=e46+subframe+failure&hl=en&tbm=isch&prmd=imvnsfd&source=lnms&sa=X&ei=d3tSUNyRJIyE9QTVm4DIDA&ved=0CAgQ_AUoAQ&biw=1024&bih=581
BimmerWill
09-13-2012, 04:55 PM
Awesome dane thanks for the vid and links. Ill do the same with my car and see if i can notice movement. Would the rtabs being bad cause such a drastic issue as well?
danewilson77
09-13-2012, 06:11 PM
Awesome dane thanks for the vid and links. Ill do the same with my car and see if i can notice movement. Would the rtabs being bad cause such a drastic issue as well?

I am no rtab expert, but I would think the rtab's would need to be gone (wasted) for there to be that much play. You said you have 1.5" of clearance. Correct?

Did you take above measurement with car in air, or with sprung weight of car?

Sent from Williamsburg, VA USA
BimmerWill
09-13-2012, 06:23 PM
Yes there is that much clearance if not more. This was with the car on the ground. I crawled in under the car tonight and was able to look at the drivers side slightly but not completely. My guess is I would have to remove that support in able to determine if it had in fact failed. I also looked at the drivers side support mount and could not see any cracks or signs of damage whatsoever..im just completely baffled at this point..

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danewilson77
09-13-2012, 06:26 PM
Mmph...so....you're going to properly support car and give it a good look tomorrow?

Sent from Williamsburg, VA USA
BimmerWill
09-13-2012, 06:33 PM
Yessir. That is the plan....ride looks absolutely smexy btw ;)
danewilson77
09-14-2012, 04:25 AM
Yessir. That is the plan....ride looks absolutely smexy btw ;)

Yes...your ride is teh smex.
BimmerWill
09-14-2012, 10:32 AM
Okay verdict is the rtabs are shot as well as the main differential bushing in the back of the diff toward the rear of the car. Im gonna get powerflex rtabs does anyone have a recommended seller for these? Just going to replace the differential bushing with the stock rubber one.

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BimmerWill
09-15-2012, 08:45 AM
Anyone have recommendation for where to get the powerflex rtabs?

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BimmerWill
09-15-2012, 09:17 AM
I was thinking here. Free shipping and the same price as everywhere else I've looked. There seems to be a difference in size between pre 02/01 and post 02/01 and my car was manufactured in 2000. Just want to make sure im ordering the right size.

http://www.bimmerzone.com/mm5/merchant.mvc?Screen=PROD&Store_Code=BZ&Product_Code=PWF-PFR5-3608-E46


Heres a link talking about there being two different sizes...

http://aakmotorsports.com/powerflex-urethane-bushings-bmw-e46-3-series.aspx
BimmerWill
09-17-2012, 07:11 AM
Okay so ordered the rtabs they should be here sometime this week. Nows the dilemma of the differential bushing. I've been browsing around on the forums looking for diys and from what I've read these bushings are an absolute pita...I was wondering if there's anyway to remove and replace the main bushing in the rear without having to drop the diff...any thoughts?

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BimmerWill
09-17-2012, 08:02 PM
Anyone? Lol

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BimmerWill
11-11-2012, 04:39 PM
New rtabs are in. Ever since I put new tires on the rear still feels a little shifty...is it possible the tires I got just don't have enough strength in the sidewall as they should? Same size same brand same model tire. Sway bars are fine I checked.

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danewilson77
11-11-2012, 05:43 PM
New rtabs are in. Ever since I put new tires on the rear still feels a little shifty...is it possible the tires I got just don't have enough strength in the sidewall as they should? Same size same brand same model tire. Sway bars are fine I checked.

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Mmm....I don't think you would feel that....but I don't knooooooow what tires you have.

Sent from Williamsburg, VA USA
BimmerWill
11-11-2012, 05:57 PM
Mmm....I don't think you would feel that....but I don't knooooooow what tires you have.

Sent from Williamsburg, VA USA

Sorry should have mentioned that.
They are federal super steel s95
Size 225/45/17

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danewilson77
11-11-2012, 06:11 PM
Sorry should have mentioned that.
They are federal super steel s95
Size 225/45/17

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I don't think that's where your rear end issues lie. Any more of a description of it feeling loose?

How old are you RSM's?

Sent from Williamsburg, VA USA
BimmerWill
11-11-2012, 06:30 PM
I don't think that's where your rear end issues lie. Any more of a description of it feeling loose?

How old are you RSM's?

Sent from Williamsburg, VA USA

Going down the interstate today around 85 I went around a medium curve in the road...as I struck the apex I looked down and my dsc light flashed a couple times. Let off the gas and slowed down quite a bit. This happened when I had a blow out a while back so I listened for that familiar thump thump from the rear. Pulled over and got out everything checked out fine. Got back in the car and up to speed again. Slalomed the car back and forth in the lane and its as if it takes the rear a good half a second longer to follow the front and then when I turn the wheel back in the other direction its like the rear comes out a little bit then goes back in following the front tires. Its like I've got nothing really holding the rear subframe solid to the body of the car so when the body moves the wheels don't follow immediately if that makes any sense. Its almost like im driving in a jacked up top heavy vehicle. Its really difficult to describe without actually being in the vehicle.

The main mount on the rear of the diff is still in need of replacement but I wouldn't think that being bad would cause such a negative effect in the handling of the vehicle.


As far as the rsm's im pretty sure those were replaced a couple years ago when I put the fk coils on.


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danewilson77
11-11-2012, 06:39 PM
Damn....that's sounds crazy.

Is it worse now, than before the rtab's were replaced?

Sent from Williamsburg, VA USA
BimmerWill
11-11-2012, 06:48 PM
Damn....that's sounds crazy.

Is it worse now, than before the rtab's were replaced?

Sent from Williamsburg, VA USA

Its better than it was. It didn't seem as prominent when I made my trip back. I don't know what's going on but it was hella scary when I was taking that turn at 85 and see my traction control light blinking.

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danewilson77
11-11-2012, 06:53 PM
Without looking at it, I'm at a loss.

Tire pressure is proper?

Sent from Williamsburg, VA USA
BimmerWill
11-11-2012, 07:03 PM
Without looking at it, I'm at a loss.

Tire pressure is proper?

Sent from Williamsburg, VA USA

Haven't checked since they installed the tires. Assumed they used proper inflation but we all know where that gets us. I will check that soon.

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