Vehicle having an auxiliary driveline with temperature responsive clutches

摘要

An all terrain motor vehicle comprises an engine 11 which may be connected by a clutch 17, a gearbox 18 and a pair for drive shafts 19 to front wheels 12, 13 and an auxiliary driveline 10 which connects the engine to rear wheels 14, 15. The auxiliary driveline 10 comprises a power transfer unit 24 having a power transfer clutch 22 which couples a prop shaft 23 to the gearbox 18. In a first mode the front wheels12, 13 may be driven by the engine 11 and in a second mode the rear wheel 14, 15 may additionally be driven by the engine 11 so that the vehicle is four wheel drive mode. In the first mode controller 40 automatically operates the clutch 22 or clutches 27 in response to an operating temperature of the vehicle, e.g. differential oil temperature or ambient temperature, so that the engine 11 or the rear wheels 14, 15 drives the prop shaft 23 and temperature of associated lubricant is increased.