A specialised fluid coupling between the engine and automatic transmission. The torque converter eliminates a foot-operated manual clutch. It allows the transmission to be "in gear" at stops and smooth, automatic and controlled take-offs and gear shifting during acceleration and towing. This system actually has no direct mechanical connection, but actually uses a rotating "fan" in a fluid to send power to wheels. When the engine turns the fan attached to it, it drives or turns the fan attached to the transmission, which sends power to the rear wheels.