1997 Jeep Grand Cherokee Limited 4 X 4. When it hits a bump it goes nuts. Uncontrolable jerking and wobbling. mechanics haven't found a thing wrong with it. It's parked. Too dangerous to drive. Help?

You would think a bad strut, but any mechanic should find that. You should have some idea if it is the front or the back. Since you say uncontrolable I will assume it's the front. The response of the steering wheel to the tires is what it should be, no delay or play in the steering? If it is as bad as you describe, it has to be repeatable. If it doesn't show up on smooth roads or at a certain speed it has to be either a strut or a broken spring maybe. It has to be something with up and down motion, not steering.