Superior Gearbox Company has been manufacturing high-quality gear drives for power transmission systems since 1975. Known for its high-quality gearbox and upbox components, Bull Powertrain is proud to be a Superior Gearbox distributor. Superior Gearbox offers high-quality gearboxes (upbox) for a variety of off-highway vehicles. Bull Powertrain is pleased to offer genuine Superior Gearbox components and offer repair and return services.