[Purdy Swoft]

I don't believe that the king pins are the problem. I have had cars with slack at the king pins that had no shimmy. Once shimmy is set up any looseness anywhere in the front end will also contribute. The problem that sets up the shimmy , must be addressed!!! I have found that incorrect toe in is usually the culprit. I set my toe in at 1/16 plus or minus a thirty second. Other possibilities that haven't been mentioned are a worn sagging front spring. Maybe the steering box is not tight enough where it connects to the frame. Are you sure that the steering arms are tight enough where they connect to the spindles. Under inflated rear tires can also cause shimmy.