When it started I would reach 40 mph and if I hit the slightest bump the front end would start shaking BAD! I’d slow down to about 20 and it would go away. I replaced the tie rod and the steering damper and it seemed to help for about 2-3 days then it got worse. Saw more slop in tie rod ends and pitman arm and replaced them. Again,better for maybe a week and it started again only worse. By this time I would hit maybe a rock at 40 mph and it would go into death rattle mode again. By now it was so bad that cars coming towards me would pull off the road till I got slowed down.
Check alignment and tires and steering unit mount-Kevin
What are you driving? A Jeep CJ with a solid axle?
If you Google “Jeep death rattle” or “Jeep death wobble”, you will find that many people have experienced this. There are fixes available and intelligent discussions about the problem on Jeep forums. Those might be a better resource than this site for your specific problem.