Hey guys,
so it was snowing a few days ago, and i skidded into a curb at about 20-40 mph. I noticed my alignment was off from then on, i took it to NTB and they said that they couldn't align it because it would do nothing positive due to a bent suspension part. They said to take it to a frame shop, so i did and they told me it was a front LH "bent" spindle knuckle. I later put in on my lift and looked at the knuckle it doesn't look bent but i bet its only a small amount of bend. What im wondering is that, can our car's front knuckle be bent going that slow??? the reason im skeptical is because they didnt run any measurements or anything and they said that they THINK thats what it is.

 

Also i can see that my Left front wheel has a little more negitive camber then my right side. could a bent knuckle cause that?

 

A bent knuckle or control arm could easily do that. 20 to 40mph is not slow while hitting a fixed object

 

f=m*V

f=3000+ lbs * 20-40

f= alot (don't feel like doing math )

 

^ haha okay cool thanks alot guys

 

also should i get a used knuckle from any junkyard, or should i buy new? thanks

 

Get new, and you should get a new wheel bearing to go with it. I'm surprised it didn't bend the compression arm, too.

 

The knuckle is made of cast aluminum.... cast aluminum doesn't bend, it cracks then breaks. Now ball joints and other non-aluminum parts could be bent causing this problem. Check to make sure your lower control arm pivot point connecting to the crossmember up front is ok. The crossmember is steel and can bend. Also your wheel hubs are steel and are probably shot. Now i'm not saying it's not the knuckle, but I doubt it... it is probably a part made of steel that is bent or something that has been pushed out of position. I know for sure the lower control arm and compression arm are made of cast aluminum as well so those are probably not bent.

I've had two accidents that damaged the front suspension and steering... i've repaired both of them myself so i'm pretty familiar with the parts. If you have any more questions you can PM me if you would like. Pictures for reference would be helpful.

Also do you have any play in the steering wheel?

 

The front suspension arms are aluminum forgings, which have much higher strength and resistance to cracking than a casting would.

 

Not sure about that... my lower control arm looks cast to me. You can see the cast separation marks around the outside of the arms. What year is your Z? Think they changed it?

But if your right I have no experience with forged aluminum... don't know what its breaking and bending properties are compared to steel.

 

The dies used in forging leave flashing similar to what you'd see on a casting. The front suspension parts are pretty simple shapes that lend themselves to forging. There may have been some minor changes, but I think all the parts were made the same way.

The rear suspension lower arm that has the bucket for the spring is more complex in shape, so it's probably a casting. There was a picture several weeks back of one that had broken in an accident, and it had snapped like a casting would fail, too.

 

okay so ive looked over the suspension on the side in question and idk whats wrong. I cant tell if anything is bent, i cant see anything broken. so is there any way to definitively know where the problem lies? I mean can i measure some stuff and compare to the other side or anything like that?? thanks for all your help

 

You'd probably have to build a jig that has receptacles and pins to fit the attachment points on a known good part, then try your part in the jig to see if it fits.

You might be able to lay a know good part on a piece of paper, carefully trace around it, and compare the outline to your part.

 

if i take it to the dealership would they isolate the problem? would they tell me whats wrong and the price to fix?

 

Yeah its tough when it isn't obvious... check the wheel hub first. With the wheel/tire mounted, and the car off the ground. Grab the top and bottom of the tire and try pushing the top in, and pulling the bottom out, then switch and try to pull the top out and push the bottom in. Doing this with a fair amount of force will reveal if something is loose. If it is, try to visually find it. Then do the same grabbing the left and right sides, push in and out and see if its loose that way. If you don't have any balljoints moving but the wheel is moving and is loose, then you have a warped wheel hub most likely. Since the impact was to the wheel this is the most likely thing to be damaged.

As for trying to find bent parts... thats hard unless its obvious which sounds like it isn't. You'll have have to spend 30 minutes or so very, very closely looking everything over and comparing it to the other side. You should take some measurements from the good side and that may help. Really this is a process of elimination, which is annoying i'll admit but you'll find the culprit eventually.

BTW did they say why they couldn't align the car? Can you get a copy of their alignment report. To help get an idea of what is out of alignment might help you find the part(s) causing it.

Oh and here are some pictures of one of my wrecks that broke my knuckle/spindle in 3 pieces. I only had to replace the knuckle and wheel hub and bearing and now my car is in perfect alignment. I slid into a asphalt curb at about 45 mph.

 

It's wroth a try... might be a guy there who knows the Z suspension a lot better than you do. Just ask them to find the problem. You can also try a few suspension shops around town. I mean real garages, not some tire shop...

Good luck man hope you get it figured out. Let us know what finally fixes it.

 

BTW if for some reason if you do replace the knuckle, be sure the replacement has whats called the "ball joint seat", in the 3rd to the last pic you can see this black cone that is around the bolt, this is where the lower control arm sits on, hence being called a seat. You can re-use the old one if in good shape, but since its pressed on you'll need to use a lot of force to get it off. I used a vice, was a little tricky but it worked.

 

^ okay good to know thanks, also i did what gregom said in post#15 and there is nothing loose, no movement with the top going in or bottom going in. theres little play in side to side but not much that its un-common. Also i went to the shop where they tried to align it and they said that the big problem was that the caster was messed up, so parts would affect the caster if bent? thanks

 

Compression arm, either bent or the bushing is destroyed.

 

is the compression arm the only thing that could cause it?, how can i check to see if the bushing is destroyed?