refect

Went to get an aligent today, and found out that something is bent in my driver side rear. I have been waiting for a bit to do my alignment, so I don't know when it exactly happened. I had a bearing fail, so I pulled the knuckle off to have a new hub/bearing pressed in. I also pulled the axle at the same time to have it rebuilt since it was spitting grease. Put everything back on and went to get an alignment.

My car was previously in an accident, and I was having alignment issues with both camber and toe on the same wheel before, but I replaced the knuckle and control arms, which then got everything to line up good. After that there was no issues on my previous alignment. This last alignment everything got lined up pretty good. Only thing now is the toe is negative on the driver side rear and has no more room on the bolt for adjustment to bring it in. I don't really drive the car hard, and my only suspension upgrades are buddy club coilovers with 18" work meister s1's.

A few months back I did hit a large chunk of concrete laying in the road. I was following behind someone and by the time I saw them go over it, it was too late to get out of the way. I went over the middle of the rock and it hit something under my car pretty hard. It sounded like it hit more in the front and not the rear though. After it happened i looked under the car to see where it hit, but couldn't really see any marks or damage from the rock. That's the only thing I can think of that might have bent something under the car. If something is even bent?

My alignment specs are...

Front left:
-1 camber
6.4 caster
​​​​​​-.01 toe

Front right:
​​​​​​-.9 camber
6.1 caster
​​​​​​-.02 tow

Front total toe: -.03
Steer ahead: .01

Left rear:
-2.2 camber
​​​​​​-.06 toe

Right rear:
-2.5 camber
.22 toe

Rear total toe: .16
Rear thrust angle: -.14

Any thoughts on what could be bent, or where to start looking? Maybe just bushings? Camber seems fine it is just the toe on the right rear that is out of wack. I don't want to start replacing parts, and spending money on parts that don't need to be replaced. Anyone have any ideas how to narrow this down, or where to start looking? Thanks in advance!

gptoyz

knuckle...it's the weakest link

after that it could be a myriad of things including:
subframe
LCA
then
UCA

The knuckle is pretty easy to tell, it should be a 90* between the horizontal and vertical, anything less than that it's bent. I've never seen a bent obtuse angle for a knuckle, usually it's always an acute angle which would account for the loss in camber.

You can also compare to the other sides but it will be pretty apparent.

RedCelica

I couldn't get less than -3.5 camber out of my left rear (where I came in contact with another car on track) last Friday. Thanks for saying the knuckle, I was definitely fixing to get another UCA. I'll try and take some pics this weekend and post them.

RedCelica

Okay so found some inconsistencies this evening when comparing the left and right sides (OP, I hope this helps you get a bead on your problem. Im not threadjacking! )







Note that the LBJ is nearly (actually I think it is) contacting the rotor shield. Also the gap between the UBJ and the rotor on the bad side is a tight 2 finger gap, where the good side is a loose 2 finger gap. I'm not a physics guy, nor an engineer, but I think gptoyz is right in saying that it's the knuckle itself that got bent, at least for me.

RedCelica

To add, just checked the clearances between the shock body and the sway bar. On the "bad" side I can snugly fit my thumb in between them. On the "good" side there is plenty of room and no contact. Wouldn't this suggest that the LCA is bent too? Or, because the alignment guy said he couldn't get less than -3.5, he has the LCA adjusted all the way in, which would reduce the distance between the sway bar and the shock body?

DefSport

Ummm, looks like both your knuckles have a crack on the upper BJ area. The first one looks really bad.

RedCelica

Same knuckle actually. Nope, other side has it too. Just a seam. Does kinda look like the seam separated a little. Good thing I ordered a knuckle after posting those pics!

Good side for comparison

DefSport

i guarantee the paint didn't dry with a crack that magically happened to line up with a stress concentrating feature on the highest loaded part of the knuckle.

Thats a fatigue crack. It might be fairly stable now, but it's definitely a crack.

Car Analogy

Can you point out the crack you are referring to? I don't see any cracks (admittedly I'm looking at picw on a cell phone).

This could be useful to others identifying cracks on their cars.

ISADE

Don't jump the gun there, I don't see any crack and I'm somewhat familiar with seeing cracks in steel. Could you put an arrow to the part you're refering to that looks like a crack?