Scary rear end feeling at high speeds!
 

Ok so i have A 2014 brz that i took to get an alignment after an acident they got the car within specs they said but whenever i exit a freeway offramp the rear end wants to slide in a violent fashion. We checked the rear end everyrhing seems solid and not loose.
The only thing that is not within specs even with a camber bolt they installed on the driver side front wheel is the front caster which is at 4.24 degrees. Any ideas?

This is interesting, I actually had the same exact issue, but it completely stopped once I got my 18x9.5 wheels and tires... Some of the things that could cause it are imbalanced wheels, bad tires, or cross threaded wheel studs, ALL of which I dealt with at once. Never take your car to cheap shops like Firestone or Midas. Anyways, I would check for these things first, if nothing in the rear is loose. I had that same frustration for weeks and it would be even worse in the rain, I would give my car 50% throttle in the rain in second gear and the TCS lights would come on! Very sketchy...


Sent from my iPhone using Tapatalk

Check if your rims are bent. That happened to me when I smashed into a curb drifting. I thought the rim was ok, until I drove on the highway and the back end kept wanting to slide out.

Check your toe arms too, make sure they’re straight and not bent.


Sent from my iPhone using Tapatalk

Just noticed the front and rear tire rotation arrow is off could this cause that

Yes, I believe if your tires are directional you can have some pulling happen on one end


Sent from my iPhone using Tapatalk

Its my fronts that are not in the right direction not rears

Should definitely fix that, but I think your rear alignment specs could also be messed up, more specifically your toe in/out... not too sure what else it could be


Sent from my iPhone using Tapatalk

Are all four of your tires directional ..??

Yep, like said, get them all spinning in the right direction for starters.


humfrz

Besides the wrong direction tires what are the alignment specs?

I made them all directional and i swapped the fronts to the rears to rule out the rims but its still happening. Ive been trying to post a pic of the alignment print out but the size is too big
I can send the pic to someone maybe theyll have a better shot uploading it?

Send it to me via message if you can


Sent from my iPhone using Tapatalk

Are you tires good? Size and condition?

most likely rear alignment, that is a textbook description for what it would be like to have a misaligned rear.

Get this car aligned somewhere else.

Directional Tires facing the wrong direction will give you the most issue in bad weather conditions.

Scary rear end feeling at high speeds!
 

Weirdly enough, I had a good alignment on the rear and still had these problems. It turned out to be I just bought some bad tires.


Sent from my iPhone using Tapatalk

Tires are good but the brand ive never heard of it before.

For anyone looking to give a hand at solving this, these are his alignment specs (I'm uploading them for him).

https://uploads.tapatalk-cdn.com/201...4fd96e1b4b.jpg


Sent from my iPhone using Tapatalk

Alright, I'll ask it. What are your tire pressures at OP?

40psi front and rear

I bet the problem goes away when you set them to 35 psi front and rear.

Does this happen turning left and right? I know most offramps are right turns but Im wondering if the caster plays a roll since its so far off? Im kinda a suspension noob and just thinking out loud though

Ill try it

Ill try and find a left turn that gives me the same results

Tire pressure didn't help

Are your rear tires sitting in the wheel wells evenly when you look at from the rear. Are you sure nothing is shifted / bent? What was damaged in the accident?

They do. What was damaged was the front suspension slightly. They needed a camber bolt to get it within specs.

But at least you're now at recommended pressures. :thumbsup:

How are the sway bars? Everything look ok on them? Maybe the front sway bar yielded in the accident and now your rears are trying to do too much work?

Thats true thank you
Ill give the front sway a once over i only checked the rear since i thought the problem would be in the rear.

Then it most likely still has something tweaked in the front, which could definitely affect the cars handling.

That brings up a point I was forgetting.

OP, If this is different than before the accident, bring it back to the shop that did the repairs and tell them they missed something. I'm assuming insurance took care of that bill? If it wasn't fully repaired that's a problem for them to fix.

Well, to get something in to specs using a crash bolt means something else wouldn't come back in line 100%. It can still be considered a good repair, but obviously something is messed up.

What kind of measurements did they take during repair? Did they check the front subframe and make sure the strut towers were true?

What was actually fixed during the repair and what was the extent of damage? You said "slight" suspension damage, but it is very easy to miss things or do shoddy repairs, especially when trying to fix it as cheap as possible.

Dude.... looking at your posts, airbags, door, fenders, seat and abs/ traction control problems. Is this a totalled car you're rebuilding? Or did you total it and buy it back / doing repairs yourself?

Lol nailed it.

http://www.ft86club.com/forums/showthread.php?t=124468

I'm all for helping a guy out, but I'd recommend letting us know what we are dealing with here so we don't waste ours and your time barking up the wrong tree.

I purchased it from copart it was hit on the b piller door and fender was replaced side airbag deployed the car was totaled out but the suspension in the rear wasn't damaged and the front didnt have much damage at all.

DANG! ....... so, we get "the rest of the story" ...... you get a light :slap: for that ....... ;)

Maybe the frame is bent or is wonky. I'd suggest you take it to a frame shop to see what they have to say.


humfrz

What kind of measurements did they take during repair? Did they check the front subframe and make sure the strut towers were true?

What was actually fixed during the repair and what was the extent of damage? You said "slight" suspension damage, but it is very easy to miss things or do shoddy repairs, especially when trying to fix it as cheap as possible.

I'll ask again, since I am genuinely curious.

I also noticed your caster is off a degree less on the drivers side, that could possibly indicate a control arm issue. I said possibly.

B piller is pretty far back on this car. From the parts that are damaged it sounds more like an A piller collision?

I agree with @Summerwolf , you are likely looking at a control arm (or sway bar) issue if you are lucky. If you are unlucky it's probably a frame or upper mount issue.

Are you braking on the off ramps? In addition to a front suspension issue, there's a small possibility of a brake bias issue. I say that because that's also where the brake hydraulics are. It doesn't try to pull to one side or do anything funny when you press the brake pedal does it?

The door was replaced fender and the A pillar was pushed in the front driver side was tweaked slightly only thing the alignment shop told me needed replacing in the future was a ball joint.

Sorry Typo i meant A pillar. No the brakes are solid the sway comes only during high speed off ramp freeway exits is when i only notice it. Ive tried going pretty fast around a corner outside of the freeway and could not replicate it.

These ^
Even using the bolt they still have not got it into spec really. There is something more severe that using a crash bolt just isn't going to correct.

Judging by everything I have read. It could be so many things causing this issue we could talk about it for days. Only thing you can do is a process of elimination. Measure one thing and keep going till you find it.