Ok I noticed this problem last time I went to the track only because I let my brother run the last pass and he was driving the car home on the freeway so I saw the driver side rear tire shimming a little.I was behind him in his girls car.Anyway I called him and told him to pull over and we checked it out.The wheel is secure and all the nuts are tight,so there are no loss lug nuts.We got the car home and it was dark so I waited a few weeks to mess with it since this is not my daily driver.My brother and I assumed it was a bent wheel so to prove this theory I swapped back wheels and it seems that the shimmy is still there on the same side.This sounds like the rear has a big problem not the wheel but it is not making any noises.These are also new tires, MT drag radials. I don't think this would have anything to do with it?Also you feel no vibrations at any speed.You can't tell the tire is shimming at all.

What is the next step? Should I take the wheel to a tire shop and have it check out? I assume it is something with the rear.What steps should I take with the rear and have you guys ever had symptoms like this.It could be a broken axle but I think you would have some kind of noise,right?

Thanks for the help.

 

Maybe a slightly bent axle?

 

Thats what I was thinking because it does not make any noise. Everytime I have been in a car with a bad axle it mad a lot of noise but thats my guess too.