Contact us for help finding the parts you need for your automatic transmission rebuild project. Transmission rebuilding does not have a “one size fits all.” Each rebuild has specific needs. We sell rebuild kits and parts so you can get what you need for your automatic transmission rebuild project. Some parts available include: Brake Bands, bonded pistons, bushing kits, bearing kits, filter and filter kits, frictions and steels, gaskets and seals, metal clad seals, sealing rings, ring kits, and thrust washers. Many hard parts are also available: cases, drums, hubs, mounts, planetaries, pressure plates, pump assemblies, shafts, sun gear, supports, valve bodies, and valve body kits. Automatic transmission can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually. Modern automatic transmissions can trace their origins to an early "horseless carriage" gearbox that was developed in 1904 by the Sturtevant brothers of Boston, Massachusetts. Recently, CVT technology has gained greater acceptance among manufacturers and customers, especially in Audi and Nissan automobiles, and gas-electric hybrid vehicles. Some machines with limited speed ranges or fixed engine speeds, such as some forklift trucks and lawn mowers, only use a torque converter to provide a variable gearing of the engine to the wheels. Most automatic transmissions are hydraulically operated; using a fluid coupling or torque converter, and a set of planetary gearsets to provide a range of gear ratios. The first torque converter automatic, Buick's Dynaflow, was introduced for the 1948 model year. A Torque converter is a type of fluid coupling, hydraulically connecting the engine to the transmission. It takes the place of a mechanical clutch, allowing the transmission to stay 'in gear' and the engine to remain running while the vehicle is stationary. A Planetary gearset is a compound epicyclic planetary gearset, whose bands and clutches are actuated by hydraulic servos controlled by the valve body, providing two or more gear ratios.To effect gear changes, one of two types of clutches or bands are used to hold a particular member of the planetary gearset motionless, while allowing another member to rotate, thereby transmitting torque and producing gear reductions or overdrive ratios. Bands are used for braking; the GM Turbo-Hydramatics incorporated this. A Valve body is a hydraulic control center that receives pressurized fluid from a main pump operated by the fluid coupling/torque converter. The pressure coming from this pump is regulated and used to run a network of spring-loaded valves, check balls and servo pistons. Hydraulic & lubricating oil also called automatic transmission fluid (ATF) is a component of the transmission provides lubrication, corrosion prevention, and a hydraulic medium to convey mechanical power (for the operation of the transmission). The multitude of parts, along with the complex design of the valve body, originally made hydraulic ATs much more complicated (and expensive) to build and repair than manual transmissions. Manual transmissions use a mechanical clutch to transmit torque, rather than a torque converter, thus avoiding the primary source of loss in an AT. As computerised engine control units (ECUs) became more capable, much of the logic built into the transmission's valve body was offloaded to the ECU. Solenoids turned on and off by the computer control shift patterns and gear ratios, rather than the spring-loaded valves in the valve body. This allows for more precise control of shift points, shift quality, lower shift times, and (on some newer cars) semi-automatic control, where the driver tells the computer when to shift.