A friend of mine has a 05 GT and is running 17x9 Cragar SS rims with Nitto 235/50-17s up front and they have balanced perfectly off of the car 6 times in a row in the process of trying to find the cause of this shimmy which occurs while cruising between 60-70mph. He has tried another set of the same exact tires on these rims but with the same result. I doubt four tires could be defective, but he might try a Pirelli equivalent on the Crager rim and see what happens. He's running Cragar 17x9's on the rear with Nitto 255/55-17. The car has been lowered with Eibach's and realigned. Any ideas?
I've run into the same thing on my Crown Vic going from a 7" wheel to an 8" wheel. The tires balance out fine, and the runout on all the wheels is within spec. I've been told I need hubcentric rings.
Take off either of the front wheels. On two of the studs, I'm betting the rotor retaining clips are still on! They are not necessary and are used to hold the rotor in place on the assembly line. They screw off by hand. If you look at the stock wheels (on the inside), you'll see a small cup in each of the 5 holes that accounts for the clip. Most aftermarket wheels don't have this cup. I had the same exact problem and took us a week to figure out!!!
I have the same problem with my 20" Bonspeeds, lowered with Eibachs, slight shimmy around 55 - 60 mph, and yes I removed all the rotor clips, it's annoying, glad I saved my stockers for long distance driving.
