which is mounted inside a casing 93 in more detail the engine 10 is as abovementioned transversely mounted in the engine room not particularly shown of the vehicle with the crank shaft 11 of said engine 10 extending transversely to the longitudinal axis of the vehicle to one end of the engine block of the engine 10 there is fixed a transaxle and clutch casing generally denoted by 12 and to the end of said transaxle casing 12 opposite from the engine 10 there is mounted a transmission housing 13 and on the engine 10 side of the transaxle and clutch casing 12 but somewhat rearwards displaced from said engine 10 there is fixed a transfer casing 14 the crank shaft 11 is drivingly coupled to a rotational power input member of the coaxially disposed clutch device 15 and a rotational power output member of said clutch device 15 is drivingly coupled to a rotational power input member or input shaft 17 of the similarly coaxially disposed transmission device 16 a rotational power output member or output shaft 18 of said transmission device 16 is rotatably mounted in the transmission housing 13 and is disposed in parallel with said input shaft 17 and further has a power output gear wheel 19 fixedly mounted on it the clutch device 15 and the transmission device 16 are of per se conventional types and function in per se conventional ways accordingly the details of.