See Figure 1
Most of the automatic transmissions used by BMW are manufactured by ZF. They are 4 speed overdrive units with torque converter lockup and electronic controls. They can be identified by a single oil sump.
All of the M50 engine and some of the M42 engine equipped vehicles are supplied with transmissions manufactured by Hydra-Matic. The Turbo-Hydra-Matic units also feature 4 speeds with a lockup torque converter and electronic controls. They can be identified by a dual oil sump.
A variety of transmissions are used, usage being determined by the chassis and engine combination. By chassis and engine, this is the application: