Ford Focus - Vibration

Question :

I have a 2005 Ford Focus ZX4 55,000 miles on it. Vibration with mph of 50+, not in steering. Causes seat belt to lockup as if brakes are being applied. Seat belt releases when slowing down under 50 mph and vibration stops. Hear noise from back tire area--driver side ie: rubbing, squealing, sounds get faster as mph increases. What could be causing vibration. ?Brakes?

Optional Information: 2005 Focus ZX$ 2.0L

Already Tried: nothing just checking for balancing problem

Answer:

I see 2 possibilities . 1) could be a busted or slipped belt internal in the tire. swapping the tires to the front and the front to the back and then drive it , if the vibration can now be felt in the steering wheel, then you need to replace the tires. 2) Could be a failing/failed rear wheel bearing. Have seen this many times. The bearing is mounted inside the rear brake drum, so if it were to fail it would allow some brake noise and wobble. Jack up the rear end , grab the tire(with it still bolted on) and see if you can wiggle it around, if so...Have the bearing replaced ASAP !!