Ball Joint problems of the 2007 Ford F-250

Hit a bump on interstate truck started shaking violently, I almost caused an accident and had to slow down to about 40 or it was going to shake me off the road, I could barely hold on, brought is it to the dealer and they said it was tire pressure, which was about 70lbs not the recommeded 75, come on that is not the problem. It is still doing it years later, wnet back to the dealer they said it was a brake hanging up and ripped me off for parts, still does it. I have now put on tires tie rod ends ball joints steering dampener, shocks and still does it. I know I'm not the only one. Make them fix this and compensate those of us who have tried to do so on our own because they won't accept that there is a problem.