Like a death wobble?

[99powerstroke]

It has only done this twice to me. I was on my original front shocks on my 99' f350 dually 2wd and had recently installed my 22" alcoa's and went around 40 mph or so over the railroad tracks and I thought my wheels were coming off the wobble was so bad.. So I replace the front shocks and now about 6 months later I was running about 40+ mph again and happen to go over a bad section in the road and it happens again so I slow down and goes away... My ball joints are the moog greasable kind are about 4 years old. I am trying to get some ideas of what it might be before I take it in to a mechanic that will tell me to replace everything:cursing:....

Thanks

 

[Betarocker]

Check everything that is part of the steering and axles. Hubs, balljoints, tie-rods, etc