Belt Tensioner A9500. View our stock to find the right part for your heavy duty needs. Gates is a leading manufacturer of power transmission solutions for heavy duty trucks and trailers. Products include belts, tensioners, engine hoses, water pumps, and system components. Gates works to produce high-quality OE and OE equivalent parts while keeping your costs and downtime down. Gates uses their expertise to solve current problems. In addition, the company invests in research and innovative technology to anticipate and solve issues. Gates exceeds expectations by investing in people and customer relationships. Charles C. Gates founded the company in 1911 in Denver, Colorado. Denver is where Gates headquarters remain today.