Abstract: A semi-trailer is provided with a pair of laterally spaced drop-leg assemblies operated by a tubular cross shaft mounted on the trailer frame. These drop-leg assemblies are widely spaced and are positioned near the side boundaries of the frame. A jaw member is mounted to turn on the frame at a location forward of the drop-leg assemblies and has an open-ended channel to accept the king pin on the truck. A pair of cables each having one end attached to the jaw member each contact the drum surface and extend partially around the cross shaft in opposite directions. Adjustable means are provided for securing one end of each cable to the cross shaft so that turning movement of the jaw member causes corresponding turning movement of the cross shaft. One end of one of the cables is pivotally attached to the jaw member to compensate for limited arcuate length of the drum occasioned by presence of the open-ended channel to receive the king pin.