1988 jeep cherokee pioneer front end

I have the above mentioned model jeep with 4liter 4x4. I have 232k miles on it. I bought it new. The problem is this. As I travel down the interstate I will hit a small bump in the road and the front end shakes violently, to the point that I almost have to come to a complete stop before it quits. I've looked at everything under the vehicle, but don't see anything loose or broken, and there is no noise. I took the vehicle to a repair shop and they replaced the track bar. The mechanic said the bar was bad. I drove the vehicle on the interstate and the same thing happened again. This happens more often in warm and hot weather than in cold. The problem is this doesn't happen all the time. Is this a symptom that the tie rod ends are bad? The ball joints are bad? What gives?