The transmission comprises a drive element on a shaft and a driven element rotatably located on the shaft. Their clutch comprises at least one clutch plate and a friction disc. A hydraulic actuator is used for the selection clutch disc engagement. The shaft has an axial passage for the fluid coolant supply to an immersion point of the clutch for heat convection. The shaft contains a transverse bore coupling the axial passage between the coolant source and clutch. The base contains a flow control valve with position change, corresponding to the clutch actuation.
