THM425

The THM425 (and later 325) is a 3-speed automatic gearbox designed and released by GM. The structure of the THM425 is based on the THM400; most spare parts in these gearboxes are directly interchangeable and some others can be adjusted with the help of slight modifications. The THM425 was designed for Oldsmobile Toronado and Cadillac Eldorado.