I replaced u-joint, lower ball joints. Had the front end aligned. service tech thought problem was at rear wheel. I pulled the drums on the wheels everything was fine,still getting shimmy

 

A tire/tires being out of balance would be the most likely problem.

 

i have the same problem, between 50-55 i get a shimmy in the front(steering wheel only), it wasnt there before i rotated the tires so im assuming its my steel wheels and heavy tires being outa balance. anything else it could be?