I have a 93 ford f150, and when i go over 25 mph it starts to shake. If i speed up to quickly, break or hit a bump the shaking gets very violent. What could be wrong with it?

 

loose front end component check the spring towers, shocks, raduis arms ect ect. something is loose and needs to be either tightened or replaced check to see if your tires are ballenced.

 

Usually a worn Tie rod bushing. In these twin I beam suspensions, the weak link. Under engineered for intended purpose.

If you have someone slowly turn the wheel, changing directions, while your standing in front of your truck, you'll see one wheel change directions slightly before the other one does. This lag is the slop that allows the tires to go out of sync.

 

Would that be the reason the violent shaking often gets worse when going around a right bend?

 

The slop allows the tires to argue as to the directing. One tracks, the other wanders.

 

OK, I just learned that my steering box and pitman arm are worn very badly, could that cause the violent shaking?

 

Any slop in the system can cause it.