2008 Nissan 350z
60k Miles
Never been in a wreck

All suspension mods:
Hotchkis Sway Bars F&R Set at the Mid stiffness
MDU Coilovers (less than 1000 miles on them)
SPC Front camber arms
SPC Rear camber arms & toe bolts


Okay, about 2 weeks ago I put my car up on jackstands, I ordered new wheels/tires, adjustable SPC front control arms, and MDU coilovers. I threw the arms and coilovers on myself.

Everything went smooth. Had the wheels and tires mounted/balanced and then drove it to the alignment shop.. Well because I threw the arms on myself, I dont know how to get the alignment even near correct, so the car felt awful.. I assumed it was the alignment causing the problem. Got the car aligned, and it still felt awful.

The car feels like it is dancing back and forth. It's really only noticeable at 60+ mph or when you get on the gas a little bit. It feels like its floating almost..

So has anyone had this problem? The car felt perfect before I installed the coilovers, and the spc arms. But plenty of people have these coilovers. Even a few people i know personally have them and never have had these problems. All swar bars are connected and really tight. I did read about the endlinks in another thread, but the fact that it only happened after the coils/arms were installed makes me think it is something else.

Any suggestions? This is going to drive me nuts..


Also, here is my current alignment I had done today.

 

Had another vehicle with that "dancing/floating" feeling, turned out to be broken endlinks.

 

Were you getting any noise from the endlinks or anything? The reason I dont think it's that is because it was perfectly fine before i put the coils/arms on

 

I hate to state the obvious, but I'm guilty of this once myself...

Put the rear of your car back on stands, remove the wheels and check EVERYTHING relating to the suspension. I'm not trying to knock your skills or anything, but something could've been missed when putting the coils on. Just a thought. Good luck!

 

I will go over every single bolt in the suspension tonight or tomorrow.. but for the time being, here are pics of everything installed. Does it at least, from what you can see, look like everything is installed correctly? Only good pics i have..

 

Well, it's impossible to tell with the pics supplied (but thanx anyways). Although they show the C/O, I can't see any connecting points other than the A-Arm. When you first get the car up, place your hands on opposite sides of the tires and try to "wiggle" it back and forth to see if you have any play. That would be my best reccomendation for a starting point to see where the play may be coming from.

 

If i have play in the wheel as you are saying, would that be a faulty wheel bearing?

 

I doubt your bearings went bad from just before to after the install. Checking for play in the wheel will allow you to see the movement real-time and hopefully allow you to see where the play is originating. Keep in mind that this may not be the issue. You just want to get the basics checked out before you have a shop tear into it.

 

Yeah definitely.. Appreciate it.

Anyone else maybe have had this problem?

 

Got the car in the air.. checked for anything loose. Tightened the left sway bar endlink a little, didnt help at all. I noticed this:





Called CIN Motorsports and they said the same thing happened on a lot of their track cars, but as long as the other end of the arm (inner lca bushing) is in the dead center of the middle brace and not toward the front of the car, then you're fine. And that was the case, so nothing is wrong there...


Random pic of the underside of the car:




Any help would be greatly appreciated!!

 

Grease coming from the ball joint boot is nothing at all. I would have them fix the rear camber, if you have the adjustable parts and they left it like that, they are lazy.

Post your tire sizes please.

 

Didnt think so, thanks. And apparently one of my rear SPC arms are frozen up, so they just had to get as much as they could with the bolts or something. But as long as its in spec it's fine right?

Tire/Wheel:
19x9.5 +12 with 245/35/19
19x11 +15 with 275/35/19

I just realized about an hour ago that I never set any preload on the coils at all. So maybe each side could have different amounts and causing the swaying motion?

Terrasmak, how tight should the front springs be? Should I let it completely loose, then just snug the spring up? Or do I need to tight it a certain amount, etc...

 

You have a good tire stagger, with no preload on the springs, each part of the car is uneven and you need to corner balance and get an alignment, also if one of your a-arms is frozen, thats the problem right there, if it has no movement how is supposed to perform? Your a-arms are what holds camber and if your camber is off it can cause the car to throw the front toe out as well and throw your alignment off, giving you that dancing floating feeling.

2. I just read what kind of coilovers you have, and the damper in thiose coilovers arent that great, this could also contribute to the floaty boat feeling, especially if they arent dialed in right.

3. You installed all these suspension parts yourself, is everything torqued or overtorqued? That a-arm i will say is whats causing the problem, especially if its stuck.

 

You probably need to add preload and reduce shock length. I bet you have little suspension travel

 

Stuart, the a arms are fine, one of the rear arms are frozen. I'm going to set the preload on the fronts now. From my understanding, the springs just need to be "snugged" up, and should still be almost the same length as if they were off the strut.

 

Set your travel with shock length, basically set the amount of up travel you have so it bottoms out on the bump stop before the tire touches the top of the wheel well ( mine is set to about 1/4 inch from the top to give room for the bump stop to compress. Then set ride height with spring preload.

 

Quick question,

I remember when installing the coilovers, on the passenger side I was able to squeeze the coilover in without having to unbolt anything, but on the driver side i remember having to unbolt the endlink and so the LCA would drop enough to squeeze the coilover in. Is it possible that I put preload on the sway bar or something from doing that?

When installing the coilovers, I had to do each corner at a time, so 1 front wheel on the ground, while other front wheel off the ground, installing.. hopefully all of that made sense.

Thanks for all of the help so far.. this is very frustrating..

 

Are those spc arms directional? Other than only other thing to question is the spring in the back? How is it seated?

 

If you mean could they be installed on the wrong side, then yes they're directional. And springs are seated fine in the back as far as I know. I will double check them though

 

Interesting, I am having the same exact problem with a set of coilovers I put on my vette. Just like you I forgot to check the pre-load and I think that may be causing the issue.