I can't seem to shake a balance issue with my 285/50/18 Nitto Extreme tires mounted on custom rims by American Eagle(5 spoke). I have had the balance checked 8 times at Firestone this year alone and the alignment checked as I have the lifetime alignment from them, the reason I chose them is that is where I bought the wheels and tires. I have tried 3 different locations and they all tell me the front end parts look good and rebalance the tires but it always, always shakes around 45mph. In recent years I have had the upper/lower control arm bushing replaced, the upper ball joints, Idler arm, Steering Gear box replaced. I really only drive it around town and to-and-from work, unfortunately the speed limit from my home to work is 45mph(the shake and shimmy zone).