i drive a 94 f350 and had the same problem twice now, i took it to a mechanic they said it was a loose wheel bearing, then it happened again so i took it back. They took it for a drive and the shake happened for them. they found a bracket that was originally riveted to the frame around the idler arm was falling off, 2 of the rivets had pulled out. they fixed it so lets hope this takes care of the problem so if you have this violent shake check the bracket.

 

"It ended up being that my lift mount that connects the axle and frame cracked then broke. Well I took it off and had someone weld it. I then put it back in and gave it a good alignment and that fixed it right up.."
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One thing that concerns me the most after reading this is that the mount would go bad in the first place.

Welding the cracked bracket may have temporarily fixed the issue but it is a matter of time before it returns....

if the mount is made of Aluminum, perhsp you should make it out of steel.

If it is made of steel, consider using a stronger alloy steel....you need to figure out what material is being used and also consider if the current design needs to be more robust.

Your safety should ALWAYS be #1.

I am going with a 3 inch lift kit and will model everything and run them through COSMOS FEA before bolting them on.

Capone

 

That once happened to me too. The base wich linked one of the TTB front suspension arms had a growing crack in it, check those.

 

I have a 94 f150 with a 4 inch lift. After changing my gears and putting my stabilizer on my truck started to shake really bad as well. It never did it before I changed the gear and had to take the hubs completely apart. Could it have anything to do with one of the hubs stocking after unlocking them?

 

Welcome to the Forums. First off, does it feel like the shake is coming from the front end at about 35 mph? I would start by checking all the bushings in your steering system. Also try jacking up one front tire and wiggling it. Act like you are trying to pull the tire off the truck but leave the lugnuts tight. If the wheel and hub assmb. moved, then you need to tighten the spindle nuts.