shaking in the front end of my truck what is it?

[pound41]

I have a friend who had 96 Ram 3/4ton 4wd. It had like 90k on it. It was only 6-7yrs old at the time He tells me that one day he is driving down the interstate and the truck bounces a few times and then its like your going over a pot holed gravel road at 50mph and you have airbags on the truck and you are jacking the bags up and down as fast as it will go. He said I have never been so scared in my life. I kinda laughed. Anyway I go one evening with him to look at a job we are going down the interstate and it starts bouncing and he says oh god here it comes And it did exactly what he said. I was scared to death. Cars were passing us and looking over disbelief. I told my dad about it he was a old mechanic dating back to the 1950's He said he had experinced it and heard a few others. He said Stop driving it and rebuild the entire front end. I would do that