Abstract: A continuously variable transmission employing a hydraulic motor and a hydraulic pump that are interconnected by a closed hydraulic circuit. An oil chamber is defined between the pump cylinder of the hydraulic pump and the motor cylinder of the hydraulic motor. A common oil cooling unit is connected through oil passages to the closed hydraulic circuit and the oil chamber for cooling heated oil supplied therefrom. The common oil cooling unit effectively cools the oil from the two sources since the heat developed in the oil from the two sources generally varies inversely during different modes of operation.