A steering system for an agricultural vehicle with a hydraulic steering motor incorporates an internal pump, a distribution valve, an input shaft which in use is coupled for rotation by the steering shaft of a vehicle steering wheel, and connectors for hydraulic lines leading to a high pressure source of oil, to an oil reservoir and to hydraulic actuators connected to the steerable wheels of the vehicle. The steering motor is located remotely from the steering shaft and is coupled for rotation with shaft by hydraulic rotary actuators mounted on the steering shaft and the input shaft of the steering motor and arranged in a closed circuit with one another.