On May 14, 2005, about 1200 Pacific daylight time, a Piper PA-28-140 airplane, N7263J, sustained substantial damage when the right main landing gear separated during landing at Pierce County Airport, Puyallup, Washington. The private pilot and his passenger were not injured. The airplane was being operated by the pilot. Visual meteorological conditions prevailed, and no flight plan was filed for the 14 CFR Part 91 personal flight. The flight departed from Auburn Municipal Airport, Auburn, Washington, and the intended destination was Pierce County Airport. According to the pilot, the landing approach "looked good." During the flare, the airplane "hit wind shear" and landed "a little hard." The pilot added power and executed a go around. He heard a banging noise coming from beneath the airplane and declared an emergency. He elected to return to the airport and landed off the runway in a grassy area. During the emergency landing, the airplane settled onto the right wing. The pilot reported that he determined the right main landing gear had separated during the hard landing and remained attached to the airplane only by the brake line. Closer inspection revealed that the two upper torque link attach lugs on the right main landing gear strut cylinder (P/N 65319-04) had separated. Both separation surfaces displayed beach marks, ratchet marks, and areas of discoloration indicative of preexisting cracks. Research revealed that on August 18, 2003, the airplane manufacturer (Piper) had issued Service Bulletin 1131, which called for an inspection of the main landing gear cylinder upper torque link attach lugs for cracks in the area where the subject cylinder failed. This Service Bulletin had not been performed on the accident airplane. An FAA inspector examined the airplane and reported that the damage included 5 puncture holes in the lower right wing skin, a collapsed wing rib, and a damaged area of rear spar cap. Additionally, there were dents in the leading edge of the right stabilator and the trailing edge of the right flap was bent.