A clutched fan drive for a vehicle engine is disclosed which couples the engine cooling fan to a member driven by the vehicle engine when the engine coolant temperature exceeds a predetermined level, and which uncouples the fan when the engine temperature level falls below the predetermined level. The fan drive includes a driving member which is rotatably mounted on a fixed spindle, a ram piston which is slidably mounted on the spindle, and a driven member which is rotatably mounted on the ram piston and which is movable therewith. The engine coolant fan is coupled to the driven member, and both the driven member and the driving member are provided with a clutching mechanism which is engaged by a resilient spring which acts against the ram piston. Consequently, the disclosed clutch fan drive requires no complicated and expensive load transmitting splines between the clutch elements and further requires no rotating pressure seals or complicated bearings which must accommodate both rotation and translatory movement.