Abstract: A vehicle axle, for example for a driven; undriven, steering or trailer system, comprises a member (1) formed as a hollow monocoque structure which includes at least one integral location (3, 20, 23) formed in the structure as a low stress area adapted to receive an attachment (24, 31, 34) thereto for use of the axle in a vehicle. The monocoque structure may be rigid, or substantially so, or it may include one or more compliant portions. It distributes throughout the member stresses to which the member is subjected when the axle is use in a vehicle and parts of the structure may be specifically shaped to suit the particular stresses to which they will be subjected when in use. In one embodiment the monocoque structure includes an axle beam part of a hollow lobed cross-section which gives roll compliance without necessarily having to add resilient components. In this embodiment trailing arms (4) are formed as an integral part of the monocoque structure which forms part of a trailing suspension system.