JASPER has been remanufacturing quality products since 1942 and today we are the nation's largest remanufacturer of gas and diesel engines, transmissions, differentials, rear axle assemblies, air & fuel components, marine engines, sterndrives, performance engines, and electric motors. The assembly process includes bolting the case to the stand (rotate the case several times on the stand while in assembly process) install and align pistons, rings, rear planet, gears, pan, pump, valve body and other parts.