Tires: Vehicle Vibration, bad ball joints, brake pads

Question
I recently did some major repairs to my truck.
I have a 2000 F150 and I replaced the ball joints (upper and lower), rotors and front brake pads. The tires on the front of the vehicle were wearring pretty bad but only the inner tread because of the bad ball joints i was told by the mechanic who looked at it for me. I know i need new tires but in the mean time I've rotated the tires so the bad ones are on the rear of the vehicle now. The truck rides okay at low speeds but when i get up between 60 - 75 mph I feel quite a bit of vibration. Sometimes when I get above 75 mph the vibration lessens a bit. Is this because of tires or could there be another problem? Also, if it is the tires what kind of damage might I be doing to the vehicle in the meantime with these bad tires?

Answer
Ray,

The vibration is probably from the tires.  Not only did the tires wear unevenly across the face of the tread, they wore unevenly around the circumference.  This is fairly common when the alignment is out.

No harm will be done to your truck - except of course annoying the driver.