A transmission includes a housing, a plurality of components, and a cooling system. The housing has a plurality of walls that cooperate to define an interior space and a sump configured to store lubricating fluid in use of the transmission. The plurality of components are arranged in the interior space and configured to cooperatively transmit rotational power between an input shaft and an output shaft of the transmission to reduce a rotational speed of the output shaft relative to a rotational speed of the input shaft in use of the transmission. At least one of the plurality of components is supplied with lubricating fluid stored by the sump in use of the transmission. The cooling system is supported by the housing.