On July 17, 1995, at 1935 mountain daylight time, a Piper PA-20, N6953K, ground looped after landing at the Ogden Airport, Ogden, Utah. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local instructional flight. The airplane was substantially damaged and the flight instructor and student pilot were not injured. During a telephone interview and subsequent written statement, the flight instructor stated that this was his first flight with this student pilot who was preparing to take the private pilot check ride. The student pilot was at the controls for takeoff and the flight stayed in the pattern to practice touch-and-go landings. During the first approach, the flight instructor stated that he took control of the airplane on final approach to demonstrate a procedure to the student. After a three point touchdown, the flight instructor noticed a strange noise and felt a vibration that he couldn't pin down. The flight instructor thought that it may be a flat main landing gear as he was having to input more left rudder control to maintain runway centerline. As the airplane slowed to 10 to 15 knots, the flight instructor stated that he was unable to maintain directional control as the nose of the airplane veered to the right and the airplane ground looped. A Federal Aviation Administration Inspector from the Salt Lake City, Utah, Flight Standards District Office, inspected the airplane and found that the tailwheel pivot bolt was loose, which resulted in the tailwheel shimmy during the landing roll. The airframe and engine logbooks indicate that the last annual inspection was performed on 12/16/93. The logbooks list several major repairs and alterations since 12/7/93.