A trailing arm assembly for a suspension includes at least first and second cast components. The first and second cast components are welded to each other to substantially surround an outer perimeter of an axle member. The first cast component is then welded to one side of the axle member at a first weld and the second cast component is welded to an opposite side of the axle member at a second weld. One of the first and second cast components includes an integrally formed air spring seat and the other of the first and second cast components includes an integrally formed bushing housing for connection to a frame.