When I hit a bump,the front end shimmies & shakes

What is causing this. I replaced ball joints & tie rod ends.

You need to have the front end checked at a good alignment shop. Something is still defective. They don’t call it a “death wobble” for nothing. How many miles are on this truck?

140,000. I replaced the parts myself & had it realigned.

I replace a lot of my own parts. The single largest reason I ever end up at the shop is b/c sometimes I know I have a problem but I don’t have the expertise/experience to figure out which things need attention. So I’ll just second that the best thing is your best local alignment shop.

if you took it to a good alignment shop he should have checked the front end for any problems before aligning the vehicle. the first thing that comes to mind for me is the steering damper (shimy shock) pretty sure this vehicle has one.

I will assume this truck is four wheel drive. Two wheel drive trucks rarely have this problem.

Your track bar is probably shot. This is common on these trucks, and between that and your steering damper being worn (it probably is), your truck will exhibit these symptoms, commonly called the “death wobble”. This issue is aptly named as if it does it at a high speed and cannot bring it under control, that is pretty much the end of your truck, and possibly you as well. If you want to check this yourself, have an assistant shake the steering wheel back and forth between 10 o’clock and 2 o’clock with the wheels on the ground while you inspect the track bar. There will likely be a worn bushing or ball-and-socket on the driver’s side (newer trucks use a bushing, older ones use the ball-and-socket). That is where they typically wear out.

EDIT: I incorrectly said drag link previously when I meant to say track bar. I apologize if this created any confusion.