I had a 2006 Wrangler Rubicon Unlimited that started the death wobble one day after crossing railroad tracks at 35 MPH.
I replaced the stock steering damper with a Monroe heavy duty unit, and that helped, but did not cure the problem.
I inspected the entire front end, and could find no apparent wear or looseness.
I had the tires rebalanced and checked for roundness.
The Jeep had a suspension lift, body lift, engine lift, and tummy tuck, custom bumpers, winch on the front and 30 gallon fuel tank in the rear.
I started having the tires rotated every other oil change, and the problem went away.
It worked for me, but I don't know why.