Tire rubbing when hitting bumps

[Firefighter]

Guys, I have a '98 M3/4 with Dinan Stage II suspension. Had Koni adjustables in the rear... I have 18x8.5 wheels with 245/40/18 tires. The passenger rear tire is rubbing when hitting bumps or if I have extra people in the car.

I thought the shocks were going, have no idea how old they were, were on the car when I bought it last year. So I bought new Bilsteins for the rear, and the tire is still rubbing in the rear on bumps.

What should I be looking for.. spring seems to be fine. Previous owner had RTAB's replaced.

Thanks!

[tmaxx445]

Guys, I have a '98 M3/4 with Dinan Stage II suspension. Had Koni adjustables in the rear... I have 18x8.5 wheels with 245/40/18 tires. The passenger rear tire is rubbing when hitting bumps or if I have extra people in the car.

I thought the shocks were going, have no idea how old they were, were on the car when I bought it last year. So I bought new Bilsteins for the rear, and the tire is still rubbing in the rear on bumps.

What should I be looking for.. spring seems to be fine. Previous owner had RTAB's replaced.

Thanks!

What offset are the wheels that you are currently running?






tmaxx445

[Firefighter]

What offset are the wheels that you are currently running?






tmaxx445

35mm offset. Only rubs on the passenger side rear. It's not all the time, but hitting a decent bump makes it rub, but really bad if my 2 kids are in the back and the wife is in the car. And NO, she is not big! LOL.

[propcar]

your tires are too tall the overall diameter of your wheel/tire is much more than what the car came with, it's probably rubbing on the fender arch and the bumper on large bumps because of your soft spring rate allowing a large amount of travel.

Switch to a 245/35 or 225/40, even a 235/40 may work.

I believe your suspension is not an issue.

[Level8drummer]

35mm offset. Only rubs on the passenger side rear. It's not all the time, but hitting a decent bump makes it rub, but really bad if my 2 kids are in the back and the wife is in the car. And NO, she is not big! LOL.

You should see my wife...what a fatass!!

your tires are too tall the overall diameter of your wheel/tire is much more than what the car came with, it's probably rubbing on the fender arch and the bumper on large bumps because of your soft spring rate allowing a large amount of travel.

Switch to a 245/35 or 225/40, even a 235/40 may work.

I believe your suspension is not an issue.

+1. Probably a combination of wheel offset (et40 is more preferable for rear suspensions on these cars) and tire sizing. Roll the fender lips. That'll fix her.

Level8Drummer

[propcar]

You should see my wife...what a fatass!!


+1. Probably a combination of wheel offset (et40 is more preferable for rear suspensions on these cars) and tire sizing. Roll the fender lips. That'll fix her.

Level8Drummer

You aint married Alex, you race too much

The wheel offset is a little lower than factory yes you're right. However the fender rolling may not even fix it.

I had 235/40/18 on my 18x8 et35's in the rear and they were rubbing on big bumps as well and I was on 540# rear springs with rolled fenders... probably set a little lower than the OP's but still, now I'm on 235/35 at almost the same height and I no longer get rubbing BUT my suspension setup changed as well now having 900# springs sooooo that probably limits the movement as well.

What I'm getting at is that the 235/40 still is a bit taller than what the M3 came with originally... but is more manageable than 245/40/18 which is wider and a bit taller I think about ~1/2" taller in diameter

[Firefighter]

Ok.. my bad.. I'm running 235/40's, NOT 245/40.

Why would it only rub on the one side? Switching tires is not an option.. these are new.

What other options do I have to take care of this that won't be alot of $$$$

[whoshaunq]

Ok.. my bad.. I'm running 235/40's, NOT 245/40.

Why would it only rub on the one side? Switching tires is not an option.. these are new.

What other options do I have to take care of this that won't be alot of $$$$

adjust camber.

[propcar]

Ok.. my bad.. I'm running 235/40's, NOT 245/40.

Why would it only rub on the one side? Switching tires is not an option.. these are new.

What other options do I have to take care of this that won't be alot of $$$$

It's still a bit of a tall tire... but should be manageable. Well on my car it used to rub on the passenger side more than the drivers. Who knows... see where its rubbing, get under there you should see some indication.

Your cheaper method is to roll your fender with a fender roller... do it right.

[Level8drummer]

You aint married Alex, you race too much

The wheel offset is a little lower than factory yes you're right. However the fender rolling may not even fix it.

I had 235/40/18 on my 18x8 et35's in the rear and they were rubbing on big bumps as well and I was on 540# rear springs with rolled fenders... probably set a little lower than the OP's but still, now I'm on 235/35 at almost the same height and I no longer get rubbing BUT my suspension setup changed as well now having 900# springs sooooo that probably limits the movement as well.

What I'm getting at is that the 235/40 still is a bit taller than what the M3 came with originally... but is more manageable than 245/40/18 which is wider and a bit taller I think about ~1/2" taller in diameter

I'm not? I guess I'll stop contemplating suicide!

And yes, with that offset it might be difficult. However with et40 wheels I can fit 255/40R17's in the back on H&R race springs. I did have to roll/pull the fenders a little in the rear when I was running koni's. Bilsteins fixed that problem (along with many others)

Level8Drummer

[scooper]

if you don't want to change tires or wheels adjusting camber is the only thing. You might also want to grind some off the inside of your rear bumper so it'll rub less.

[Firefighter]

I put on the bilsteins, helped some, but with a car load still rubbing and runs REALLY bad if going around a sharp curve and the car rolls to that side. Still think its camber??

[Bimmerman535i]

Ditch the 18s for a shorter 17" tire, only way you'll solve the problem without taking a roller to the fenders.

A 235/40/18 will still rub stock fenders at a (reasonably) lowered ride height.

245/40/17 is probably the best tire for a primarily street E36 as far as grip, fitment, price, and tire availability go. 235/40/17 is even better, but much harder to find.

[Firefighter]

I'll have to try rolling the fenders I guess, switching to 17's not really an option. Had 18's on my other M3's with no issues. Can't remember what size tires though.

Is there anything else, bushings, etc... That could be causing the problem or you guys pretty confident it's just the tire size?

Thanks!

[CaptainBlueFoot]

I have this issue, but my car is lowered with bilsteins, my rear tires are rubbing on the wheel well, fenders are already rolled. I'm running 255/35r18. Lexani sells affordable tires in weird sizes. Im trying their 245/25r18 tire next and seeing if it'll stretch on and if that'll solve it. That's as small as you can get on the tire though, I think. That's if you really don't want to raise the car or go down on the wheel size.

[TostitoBandito]

Is your ride height adjustable? Just raise the car until you figure out how to make your tires fit at your desired ride height. As many have said, wider or low-offset 18's will have fitment issues on stock E36 M3's. The car was designed for 17x8.5 ET41 245/40-17's in the rear. You can't really go much wider or bigger than that in back without an even higher offset, or fender rolling/cutting/widebody. The fenders don't flare out very much and leave very little room for more tire. People generally try for the highest offset wheels they can in back in order to get them as far away from the fender as possible and allow the biggest tire.

Also, as others have said, camber makes a significant difference in wheel fitment along with ride height. The more negative camber you have, the more the top of the tire tilts inward and away from the fender lip, giving you more clearance. You may need to run a more aggressive camber configuration to make larger wheels fit correctly.

[cretinx]

take a hammer to the fender, or raise the ride height, or change tire diameter