My old Mustang had a bad wheel bearing at one point. At speed it would cause a vibration in the steering and make a grinding sound that got faster as the speed increased. It would also go away when steering slighty left and be more constant when steering right. Jack the car up and check for play on the wheel.
I'm not sure about contours, but the Mustangs have a whole wheel bearing assembly that has to be replaced to replace the bearing. It came prepacked and everything. Anyway, good luck.
-Matt
