Rear subframe bent?

[OMBGodfather]

Hey everyone, I picked up a 97 m3 sedan and I'm wondering if the rear subframe is bent. I've gathered that the car was in an accident on the rear passenger side but I'm not sure how bad. The rear passenger tire is tucked I to the wheel well farther than the driver. After changing all the control arms and bushings the last thing to check (besides shoddy bodywork) is the subframe. Anyone have any tips or good measurements I need to look for?
Thanks


IMG_20200607_143115035_HDR.jpgIMG_20200607_143105960_HDR.jpg

[Hova]

Usually it's the lower control arms that bend. Check those first.

The control arms are on eccentric bolts as well, it's possible that they are not set correct and the car it out of alignment.

[OMBGodfather]

Those are all replaced from a donor car. The upper control arm on the passenger side was bent but these pics were after they were replaced. I know about the eccentric bolts on the bottom and even though I still need an alignment the wheels are close to similar camber.

Update: today I changed the subframe from a donor car and even though I found a wallowed out control arm hole, the wheel is still set in more than the driver side.

[blckstrm]

Did you check the wheels?

I know it sounds stupid, but if that tucked wheel is a front wheel that would explain a lot.

[TostitoBandito]

Subframe is probably not gonna bend. You're gonna bend or break control arms and half shafts and everything else before you do anything to that giant hunk of steel.

Aside from measuring and inspecting the control arms, I'd focus on the body as well as the wheels and tires as previously mentioned. Your pictures are showing differences in gaps from fender panels to wheels. If you have a body panel which isn't straight or is otherwise different than the other side (maybe due to repair) it could result in what you're seeing despite the actual subframe and suspension components all being straight.

Also, a professional alignment would be able to quickly reveal if anything is really amiss in the rear suspension, or if this is just cosmetic.

[blckstrm]

Alignment is a good idea.

In fact, just do this in your driveway. Mark the pavement at each wheel and see if the car is square. If it is, it's more likely a body panel issue. If not, you can keep digging on the possible mechanical causes.

I'd still check and make sure you don't have a front wheel on one side and a rear wheel on the other.

[TostitoBandito]

I too suspect a front/rear wheel combo, but I know on my car there are small differences side to side in how much fender clearance there is. It's not nearly as drastic as in this case, but it's not quite symmetrical either. I suspect it's from when my dad (the original owner) spun the car into a guardrail and had some body panels replaced back when he owned it. It was all repaired but it's maybe a couple mm different side to side, which you notice when like me you're trying to get the rear end as low as you possibly can over wide wheels and tires. In any case, the suspension is 100% perfect and straight which I know because I've refreshed all of it and been through every single part. It's just the fit of the body panels to the car. I also imagine that if someone cheaped out on a body repair in the past it could be a lot worse than it is on my car, which was spared no expense by all accounts.

[blckstrm]

I don't think they're ever perfectly symmetrical. I'm in the same boat fitting lower offset / wider wheels in the back, and they're just not the same from side to side. It's just a few mm, but it's not identical. It was like that before I got hit in my right rear wheel (literally perfectly - broke the trailing arm and a spoke on my wheel, bent both control arms, didn't touch the body) and it was the same afterwards.

But it's not what you're showing.

But we're going in circles now. We've suggested some things - let us know what you find.

[smr87]

I also have this problem, and haven't been able to pinpoint the cause. I only noticed it after I dropped the rear subframe to replace all the bushings/ball joints. I've dropped the sub-frame and double checked it is not somehow cock-eyed multiple times subsequently and I still have a mismatch side to side. I'm not sure if it was there before I did all the work or not, my car is like a pinball so it could just be poor body alignment since it drives straight and was aligned without issue.

[OMBGodfather]

It's not the wheels. Like I said earlier, I changed the subframe and did find damage but still not enough to fix the clearance issue. I've pretty much resigned to bad bodywork. New tires though so there's that lol.

received_296699781376766.jpegreceived_947679825646236.jpegreceived_636427063624345.jpeg