I have had the death wobble bug before.
start with tighting up the shackles
then make sure your ubolts are all tight
then have a friend get in and wiggle the wheel back and forth slowly look at your tie rod ends if there is any lateral movement on a rod end replace it.
it will mainly be one of those places mine was a bad rod end so I ordered 4 new ones and did um all and it took the wobble away.
