Vehicles with automatic transmissions have a flex plate. Flex plates connect the engine and transmission. Most flex plates are made of a thick piece of sheet metal with bolt holes for the torque converter and teeth for the starter. The ATP heavy duty flex plate offers superior strength because the ring gear is welded on both sides to the center plate. The job of a flex plate is to allow for expansion of the torque converter as engine RPM increases. The constant expansion and contraction of a flex plate over time can result cracks and/or shearing of the flex plate. A damaged flex plate can create serious (expensive) damage. Broken flex plates can not be repaired, they must be replaced. ATP flex plates are made of high quality steel and contain the correct bolt hole spacing and ring gear teeth just like the original part to ensure long life and durability