I recently installed double adjustable spherical LCAs on the car in my signature. I adjusted them to be the same size as the stock ones, but one jam nut came loose on one side while I was installing it and it moved slightly. I then adjusted it by measuring bolt to bolt on both sides (they were already on the car), as well as measuring from the tire rim lip front to back on both sides. They appear to be in good measurement (within 1/16" or less of each other) and the car drives straight, BUT only on a perfectly flat road. If a semi or large truck passes me, and sometimes just in general the back end up the car will sway hard and push the front of the car in a direction of its choice. Basically the back axle is trying to steer the car.

Is rear steering/sway normal after putting on a stiffer/solid LCA? Or is this a sign of still not being adjusted properly?

I notice this especially when accelerating. It will steer right a good amount, and when I let off the gas it will go back straight/left.

 

It shouldn't make any difference being that close, was anything else done to the car at the same time ?

 

I replaced the fuel pump at the same time, but none of the other suspension components where changed. I am starting to think this is normal since the car tracks perfectly straight with no pushing/pulling when on a good road. When on a bumpy/crappy road each side of the axle will go up and down separately just a little bit, and that will push/pull the car since there is no longer any rubber bushing to take the brunt of the force.

 

Did you tighten the suspension bolts/fasteners with the car at ride height?
Are the swaybar endlinks loose, worn badly, or bent/damaged?

 

shake (push) the car form sise to side in the back. (check to see if there is excessive movement) it could be that the panhard bar is lose or bushing is shot...
I just had the same problem with my car and could not figure why the car would wobble back and forth and realizes the poly bushing were shot

 

The swaybar end links were replaced when I did all this, and they are not bend or damaged. The panhard bushings are good as I had it out when I was replacing the fuel pump and I gave everything a twice over. I am thinking it might be partially due to the panhard bushings being the stock rubber and not being able to hold up like the spherical rod ends can. Either way, I am starting to think it is more normal, and I am in the process of making a new panhard bar with spherical ends.

 

You said the car" sways" at hard acceleration, I would take that as a sign to recheck your adjustments and maybe start to find your own setup until this problem stops, but if your fabing a panhard bar wait until its done and installed. The whole point to the adjustable LCAs is to adjust for best traction and launch, so if it sways its prolly out of wack

 

I guess "sway" is not the best word to use. It actually pushes the front of the car to the right on acceleration, and pushes/pulls back left when I left off the gas. If I cruise at a steady speed the car will track perfectly with no swaying/pushing/pulling. The only time it feels like it "sways" or when it pushes is when the road is bumpy. When my panhard bar is done and installed I will see what it is like then.

 

Sounds almost normal.... but I do suggest a full 4-wheel alignment with thrust angle measurement/adjustment to make sure everything's straight and square.

 

Did you tighten the sway bar endlinks with the suspension loaded?

 

Sounds like the LCA's are not the same length.

 

Yep, I took them off and adjusted them again, they were about 1/4-1/2" off from each other. Everything is normal now. And for anyone's information in the future, putting a small piece of heat shrink around the bolt and then putting the LCA in (for spherical rod ends that make a lot of noise) will dramatically reduce the noise.

 

Are you saying that you slid a large (diameter) piece of heat shrink over the threads or a small (diameter) piece wrapped around the threads?

 

The bolt is a 12mm, or almost 1/2" so I took some 1/2" heat shrink, slid it over part of the threads and the non-threaded area just before it goes to a larger diameter (otherwise the bolt won't go back through the mount holes). Heat it up and it shrinks down snug on to the bolt. Worked wonders

EDIT: and I did this with the bolts off the car.

 

Ok, that makes sense. I misunderstood and thought you slid it over the threads of the adj rod ends. Thanks for the tip