I have a friend witha 98 Explorer, and it has a front end shimmy above 60mph. She has replaced lower ball joints, 2 new tires with front end alignment, all 4 tires balanced, and still a shimmy. We've heard of everything from another alignment to wheel bearings. Upper ball joints were "checked" by a garage, and are supposedly OK. Any help is greatly appreciated.

 

I would double check the tie rod ends. I have replaced numberous tie rod ends to fixa front end shimmy that nobody else seemed to be able to. If it's a whole vehicle shimmy it could be a worn or bound up U-Joint. If it's a 4WD, it could be a front axle shaft joint.

 

Had the same problem and found out that I had to replace the hub assembly on both sides and get an alignment. Fixed the problem. Good Luck

 

Could be Shocks?; are the tires in good shape with no cupping?