I just bought a 1988 super duty diesel. Most of the time somewhere between 35 and 45 MPH it starts shaking violently. I have tried driving through it and it continues on through at least 60 which is when I let up on it. It doesn't do it everytime but at least 90 percent of the time. I know the steering linkage is tight ball joints are good and steering stabilizer seems good. I'm about to rotate the tires and see if it helps.
Oversized tires will do it also. I had the death wobble after I went with larger tires, dual steering stabilizers helped reduce the wobble alot.
I had an issue with death wobble when I first purchased my truck. I've heard all types of remedies like checking bushings, ball joints, making sure shocks weren't worn and a combination of other things. I had bought a dual steering stabilizer hoping that would solve it and got it realigned and nothing worked. I though I was out of luck but then a friend of mine had told be about the Readylift adjustable track bar so i figured I would try it if it would get rid of the wobble. I put it on and it was a life saver. I've had it on now for about a year and haven't had any issues.
