Disclosed herein is a one piece drive shaft housing comprising a casting including an outer surface having an upper end surface, a lower end surface, and an endless side surface extending between the upper and lower end surfaces, an internal cavity extending between the upper and lower end surfaces and adapted to receive a drive shaft and a clutch operated linkage, an internal exhaust gas passage extending between the upper and lower end surfaces and located in spaced relation to the cavity, an internal coolant supply passage extending between the upper and lower end surfaces, an internal idle exhaust passage including a series of expansion chambers and extending between the upper end surface and the endless side surface, and an internal coolant drainage passage extending between the upper and lower end surfaces in heat exchanging relation to the exhaust gas passage.