I don't even know where to begin so many possible causes and money in short supply.
I'll start with I bought my 93 5 spd f150 4x4 short bed with a 4.9 an approx.93xxx miles, 4 inch lift w/ newer 31's roughly 3 months ago, she has the usual problems that come with a older vehicle. Only major issue was a brake problem. I had to replace a brake line. Then the rear brakes locked up which still need fixed correctly. (After beating the drum off the driver side rear) I disengaged the parking brake that caused it to happen an put the drum back on. The truck stops so wasn't worried bout replacing shoes at the time. Thanks to pasted experience I checked if the rear sway bar was there an like before it was gone (I don't know why people remove them when lifting a truck around here) I had a set of lateral bars from my bronco I put on it to solve that. And we'll slowly the front end began to shake. The previous owner had replaced the radius arms and put a single steering damper on recently by the looks of them. They only had 2 bolts holding them to the frame so I added 2 more to ensure they are snug an not gonna move.the wobble got worse I replaced the passenger side tie rod end 2 days ago and lastnight I hit a pothole and bout lost control. She wobbled so hard I cracked the radiator at the top near the hose and my newly welded on exhaust fell out before I could stop it. I looked under the truck an looks like previous owner removed the front stabilizer bar also. My core support is about rusted thru I don't know if that has anything to do with causing the death wobble. Oh ya and the driver side rear shackle is also rusted almost completely thru and the shocks or spring is shot. I think that is it. My previous truck wasn't wobbling as bad I poured a bunch of money into trying to fix it even went as far as swapping the front end out. Gave up and sold it. Now Its starting all over and I don't have the funds like before. Can someone help I don't know what to do this time.

 

Sway bars were optional equipment, that truck may have never had them. But, it shouldn't cause your death wobble. What speed does this happen?

How are the ball joints & axle pivot bushings?
Wheels & tires?
Is there a drop pitman arm on there to keep steering geometry in check?
​Caster angle?
Tie rod ends?

Put a wrench on steering box mount bolts and make sure they're tight. While you're there, check the frame in that area for cracks.

​​​I'm not a death wobble doctor, just putting ideas out there..

 

EVERY suspension component must be tight. How was the lift done, professionally or a hack job? You mention rust. Worst case scenario, Perhaps the frame is rusted enough it is flexing. Core support should not cause death wobble.

 

There really isn't any certain speed all depends on road condition( pot holes and such) the ball joint bushings don't look to bad, wheels look fine and don't seem to be any unusual wear on the tires either. I have a drop pitman arm on it to be honest I don't know if it's right or not..I can see the spindle and I don't know how much showing is normal.I replaced the passenger tie rod end yesterday and I need to replace all the bushings but they aren't bad enough by looks to raise concern I don't think.and caster and camber angles I can't figure that crap out ever. It's Greek to me for some reason. I looked at the steering damper it's seems a bit small and honestly looks like it was just slapped to answer if it was a professional or hack job its hard to say I founderstand the receipt for putting the lift on and it states gear box loose, but looking at how it's put on makes me think hack job. Also the spring and shock set up seems to be missing pieces. If it did come wit out a stabilizer shouldn't it still have the cup thing that goes over the bottom of the spring for suport?

 

Also the core support is worse then it was prior to the wobble that damaged the radiator it's looks fully separated now if I can figure out how to load pics I'll snap some so you can see what I'm dealing with

 

It's a problem in your suspension, or as said above, cracked frame. Check around the steering box for tears.

Other than that, it's pretty simple (whether you want to believe it or not): you have worn parts. Check ball joints, tie rods, radius arms, pivot arms, and even check steering box for play.

Death wobble isn't a mystery, don't treat it as one....just check the parts.

 

A mystery? Obviously I know something is broken and needs fixed. I have dealt with this on a different truck. I wasted alot of time ,money and effort on that endeavor without prevail. And didn't put thought into it and done wisely without breaking the bank. So not a mystery sir more like tricky. Cause I gotta narrow it down and fix the broken part without breaking the bank. And thank you for the suggestion. I am unsure exactly what I'm looking for. Maybe you can answer my previous question how far should the spindle be slid out on the gear box. It don't seem right. Also I noticed fresh liquid on the top of the it.it's odd placement. What would my next move be what would tears be exactly it's a study box

 

"Ball joints look good"....how??

Pivot bushings?

Death wobble is not easy to get with the ttb, whatever is worn has to be obvious

 

Consider checking the axle pivot brackets for bolt tightness as well as cracks in the brackets themselves. I have found the right side unit (the one to which the left axle arm mounts) is prone to cracking.

dn.

 

I was going to post this almost word for word. Do this first, before doing anything else. Those lift brackets put a lot more stress on the crossmember, and if those bolts come loose, the leverage alone is enough to crack the crossmember, causing the bracket to tilt a bit, which is enough to throw your castor angle off enough to cause a DW.

It happened with mine with a 6" lift, which uses the same bracket as a 4" lift. Gave me a good reason to go with a solid axle...

 

I never noticed the change, but what's with the lift brackets nowadays that are two measly pieces coming off the cross member? I have two lift brackets of 90s vintage that I refuse to get rid of because they are beefy one piece units.

Also the f1fiddys don't need lift brackets to tear the cross member, I just fixed one that was completely torn on the drivers side, as well as cracks all over and around the steering box...325k miles and I don't think it ever saw any dukes of hazard type stuff...just normal use for a long time.

 

I agree with the above. In addition you might want to check your tire balance.

 

take your truck to a decent suspension shop, get them to check things and give you an estimate for things. someone that does this for a living has a fair amount of experience and can see things that are wrong quickly.

then you can figure out if you want to try to fix things yourself or get some help. also might tell you if the truck is still worth putting money into it.