I was driving last week and all of a sudden it sounded like I had a flat tire, I also felt the tire shaking(Passenger side).  Doing about 65mph.  Then I heard it break, the axle broke .  Got a new one put on and it still does the same thing, shakes and sounds like it is a flat tire and it does it at 60 mph and up.  Can anyone help me?  I have a 96 Z24, automatic trans.  Tire, rim is not bent, just got it balanced yesterday.