95 Grand Cherokee, 146K miles on a clean well maintained southern truck. 4.0 engine, 42RE auto trans, 4-wheel drive with the factory Dana 30F up front(with u-joints not CVs)and the 35C axle in the rear, factory aluminum wheels with 235/75/R15 tires.
Problem: when at highway speeds going around left sweeping turns the left wheel oscillates back-n-forth (horizontal plane not vertical)rather violently when hitting a bump on the drivers side wheel, steering wheel shakes also. Doesnt do it when going around right turns. I have to slow down and apply the brakes hard to get it to stop shaking. That was the problem before replacing most of the steering parts(in/out tie rod ends,drag link,steering damper,shocks,front axle u-joints,front/rear stablizer bushings,alignment,balanced tires,adjusted the lash in the steering box etc...etc). Now its not as bad but still does it occasionally?? I have inspected this thing and I dont see anything loose. Anyone else run into this on a mid-late 90s HEEP? I was thinking wheel bearings, lower knuckles or upper ball joints but they appear tight when its on the lift? Thats all thats left to replace. Thanks. Steve droldsmorland@hotmail.com  

Change the ball joints, upper and lower. If that does not help change the unit berrings.  

cheek and make sure your brake roters aren't warped.also can you tell me where you got the cv to u joint set up for your front axle  

Sounds like classic 'death wobble' to me.