Hoggy, I just cured that same on my ford 450. The shimmy started a couple of years ago so I put on a new steering stabilizer and it went away. It was gone for over a year and then returned. At 45-50 it would go into violent front end shake and I'd hit the brakes and slow down and it was gone.
So I stopped by a front end shop and the chief wrench looks at it and says... I think you need new tires.
The tires still had good rubber so I went home and parked it and started on the wiring changes I needed for a new trailer.
A few weeks later I walk up to the truck and notice the left frt. looks weird. The darn tire had split open on the tread surface with ply separation.
The guy was right, two new front skins and problem is gone.
The hard part of this was replacing the tires when they looked good.
Dan
