Usually these things are CV joint related or bearing related. With the wheels straight a head and no jack under it, see if there is any movement in any direction of..any front CV joint...mostly the outers. If none, jack each side up and see if you can get any movement out of the wheel bearings. The brakes will make this tough. Also look for any extra or odd wear on the rotors. Look for rocks or sticks while down there rubbing the rotor or wheel.