Abstract: In order to more easily control movement of a vehicle such as a tractor, an operator's left hand can twist a directional actuating member or a juxtaposed speed actuating member about an outstanding axis. These actuating members are rotatably mounted on a tiller arm extending radially from a housing assembly so that the operator can simultaneously use the actuating members and steer the vehicle by pushing or pulling the tiller arm and rotating the housing assembly in the desired direction about an upstanding axis. Push-pull controls are associated with each actuating member and protected within the housing assembly. A bearing assembly guidably supports and permits relative angular movement of each of the push-pull controls to prevent twisting thereof when the housing assembly is rotated.

Abstract: Structure for mounting a bulldozer assembly to a vehicle, such as a tractor. The mounting structure includes lift jacks connected to a radiator guard extending about the vehicle engine coolant radiator. The mounting structure includes a portion connected to the lift jacks and a portion received in a socket provided in a corner portion of the radiator guard. The mounting structure includes structure for removably securing the same to the radiator guard.