Abstract: A prop assembly including an elongated prop leg is provided having one end pivotally mounted to an associated vehicle dump bed for swinging movement between a first generally horizontal retracted position when the dump bed is in its lowered position and a second depending operative position with one end of the leg inclined downwardly when the load bed is in a raised inclined dumping position. Structure is provided for limiting swinging movement of the leg toward its lowered operative position with the leg angularly displaced relative to the bed less than that angular displacement from the retracted position of the leg which would allow the leg to depend vertically downwardly from the bed.