shaking like crazy

[1967moustang]

I can't get my car over 55 mph with out my rearend going crazy. Its sliding all over the road!!! Whats wrong ??? I need help now!

 

[2nd Mustang]

Loose wheels? Worn rear axle bearings? Loose front wheel bearings?

Mine was jumping from side to side on the freeway when hitting any irregularities on the pavement on the freeway. It was my front wheel bearings being loose. I inspected, repacked and retorqued them down to cure my problem.