My 94 F-150 just started acting up. I was getting a vibration at about 65 mph. So get the wheels balanced, right? Nope, it didn't fix it. It only happens at the 60 or higher mark and upon acceleration from there. I can let off the accelerator from 65 and it is still there down to about 55. There is more vibration on acceleration from there. Please help, it is at the point of frustration.