Abstract: A suspension system for a vehicle road wheel comprises a wheel suspension device (1) having a double-acting hydraulic actuator and a gas spring in parallel, the gas spring being controllable to provide a selectively variable offset, a sensor (6,90) arranged to sense load changes experienced by the suspension device and to provide an output dependent thereon, and control assembly (95) responsive to the sensor output to effect adjustment of the hydraulic actuator pending change of the offset of the gas spring to accommodate the load changes. Also disclosed is a damping system for damping movement of a piston (64) within a cylinder, the damping system comprising a valve (80) operable to connect spaces (70,74) within the cylinder at opposite sides of the piston to fluid pressure and/or return lines (84,85) so as to apply selected positive or negative damping to the movement of the piston.

Abstract: A torque splitting device (12) capable of use in a four wheel drive road vehicle has two coupled epicyclic differential devices providing the two outputs and connected respectively with a torque input shaft (30), which may be driven by a vehicle gearbox and a control shaft (35). The control shaft is driven from the input shaft (35) by way of an infinitely variable ratio drive means comprising a fixed displacement hydrostatic motor (51) coupled with a variable displacement hydrostatic pump (50) which is controlled by signals from a control unit (60). The unit (60) may be responsive to signals representing vehicle control and/or experience.