The Automotive Parts Rebuilders Association (APRA) is an association of over 1800 member companies that rebuild automotive related "hard" parts, such as starters, alternators, clutches, transmissions, brakes, drive shafts, and numerous other parts for passenger cars, trucks, off-road, equipment and industrial uses.
www.apra.org

  
PTDA is an US-based trade association representing almost 230 power transmission/motion control (PT/MC) distributor firms with almost 3,000 locations throughout North America and 15 other countries, as well as over 190 manufacturers that supply the PT/MC industry.
www.ptda.org