On May 19, 2005, at 1000 eastern daylight time, a Piper PA-32-260, N3936W, collided with a taxiway sign during a landing roll on runway 23L (7,526 feet by 150 feet, dry asphalt) at the Willow Run Airport (YIP), Ypsilanti, Michigan. The pilot and passenger were not injured. The airplane was substantially damaged. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The local flight originated from YIP at 0956. The pilot reported that after a local flight they entered a left downwind for runway 23L with the tower reporting the winds as being from 150 at 12 knots. The pilot reported that he established a left crab on final approach to stay centered with the runway. He stated that as he flared, he applied right rudder and left aileron. The pilot stated he touched down on the centerline, but the airplane began drifting to the right as the nose wheel touched down. He continued to report, "I again determined I had full left aileron into the left crosswind and applied more left rudder to steer the aircraft back to the centerline." The pilot stated he applied as much left rudder as he could; however, the airplane continued to turn right until it exited the runway and struck a taxiway sign. Airport personnel reported the airplane veered off the right side of runway 23L where it contacted the Taxiway Fox sign. The sign was knocked off of its mount and it came to rest 16 feet from the mount. The airplane came to rest 200 feet off the side of the runway. Inspectors from the Federal Aviation Administration Belleville, Michigan Flight Standards District Office inspected the airplane after the accident. The inspectors reported that they inspected the brakes, rudder, and steering systems, and no defects were noted. A mechanic who inspected the airplane for the pilot reported the clevis bolt on the landing gear was loose allowing the horn assembly to work back and forth eroding the attach bolt. He reported that this in addition to excessive wear on the lower torque link, bushing inserts, and damper assembly allowed 10 to 14 degrees of caster on the nose wheel assembly. THIS CASE WAS MODIFIED OCTOBER 12, 2006!!