Alignment assistance
Y'all got me here talking about ladder bars. Was in the middle 1970s, Was a set of brothers near where I attained driving age, and I think was 7 but usually was only 3 or 4 come to town to cruise on Friday or Saturday nights. They were workers, good guys, family had a large farm. One of them like to rip up and down in a '67 Camaro, had a BBC, likely was a 396. He also had a set of Marsh Sprinter rear tires, 11.00x15 on deep Cragars, and the longest ladder bars you seen. The ladder bars hung to within a few inches of the road in back, but they tapered towards the front where they pivoted under the front floor to the front sub frame. This boy had a temper too, and always seemed to carry a chip on his shoulder. One night a best buddy dusted him with his GTO out on 29, and then later he come through Lendy's raising hell. His brothers packed in the car, he was mad for some reason, or just being stupid maybe. An hour or so later, we saw them at another burger doodle, and my buddy stopped and did a burnout, which just fired the boy up. He come out after us, as was only us two and 4 of them. And according to plan my buddy turned in through the Kroger lot, where there were speed bumps then, new tall ones. We slowed, tip toed over the bumps, then went on. He tried to follow that GTO over those speedbumps, but the Camaro stopped as the ladder bars picked the rear tires up off the road, We circled back through, there the 3 brothers were, pushing that Camaro backwards off the speed bump. Anyway, we thought it was funny.
Was a '65 GTO, with a nice 400 RA out of a newer Goat, with some nice updates. Transmission and re-geared 12 bolt rear from a '69 Chevelle.
And now that I've finally fired it up, I gotta' get ready to head out to work again.
Darn this retirement anyway!
Yes. Certainly when the conditions are right. In fact, if a particular vehicle is prone to it, several things can set off the impending doom of the DDW's (dreaded death wobbles).

I was doing 75 in the go fast lane....at night and hit a bad spot in the road where a bridge and the pavement meet. All on a 4 lane and the seam is at a angle. It came on in the blink of an eye, and I was along for the ride trying to get it shut down and not hit any one, change lanes unwillingly, and keep it outa the center medium/ditch.
I got it shut down and the wobble finally went away at 25 MPH. I then pulled off to the slow lane shoulder and got out to inspect, expecting to my steering box had fell out or all my tie rods had broke.
Hitting a bump just right, hitting a ripple in the road at the same place at the same speed, or, as in many cases (like yours)) hitting the transition between road segments or railroad tracks at just the right angle for your particular setup.
How does seat foam taste by the way? Haha!!! Good one!
If it does it again, rotate a front tire to the back. One side at a time is best. If it's just one tire that is causing this, you can find it this way.
If it's a gaggle of things, such as some more steering components going bad (along with a tire most likely) this test may not result in a quick answer. Or if it's more than two tires, you're just plain screwed anyway!
Paul












