Lincoln Aviator Steering Problem

Hello my name is Dean and I have a 2003 Lincoln Aviator 4.6L V8 that I had just bought from a dealership with 56k miles. The dealership replaced 4 new tires that are BF Goodrich and they cut the brake rotors because of shake in the steering while driving. The problem im having right now is that when I come to 80mph the steering wheel starts to shake rapidly and ive also noticed that the steering wheel istself looks that it is turned 10 degrees to the left when the car is driving perfictly straight without shake untill 80mph when it starts to shake. The car is still under warranty for 30 days from the dealership however they are an hour and a half away. So if its something simple ill do it myself or check it myself and if its something serious then ill have to make the drive. Do you have any ideas on what could cause this shake and the cocked steering wheel and or what to look for to figure out whats wrong? The help would be greatly appreciated!