Abstract: A side panel which is openably and closably mounted on a bed of a load carrying vehicle includes a pipe in which a compression coil spring is disposed with its one end secured to the pipe. The other end of the compression coil spring is connected to a guide plate movable through a slot in the pipe and pivotably coupled to a link pivotably connected to a frame mounted on the bed. The side panel can be angularly moved between the open and closed positions with a small manual force with the aid of the resiliency of the compression coil spring. The secured end of the compression coil spring is positionally adjustable within the pipe so that the resilient force of the compression coil spring can be varied. The compression coil spring is held in frictional engagement with the pipe to allow the side panel to be brought to a stop at any desired position between the open and closed positions.