A loading ramp assembly comprises a ramp body, a pivot bar, a first clamp and a second clamp. The ramp body includes a detent. The pivot bar includes a bore that receives the detent. The first clamp is disposed on the first side of the pivot bar and the second clamp is disposed on the second side of the pivot bar. The proximal end of the ramp body is rotatably connected to the pivot bar at a position on the pivot bar between the first clamp and the second clamp. The ramp body is rotatable on the pivot bar from a loading position to a stowed position and is also inwardly and outwardly slidable on the pivot bar. The first clamp and second clamp can assume a loosened configuration and a clamped configuration. In the loosened configuration the pivot bar is rotatably positionable such that the bore can assume a selected angular orientation. In the clamped configuration, the first clamp and second clamp apply a clamping force to the pivot bar that holds the pivot bar in a clamped position and maintains the bore in the selected angular orientation. One or more fasteners removably fasten the clamps to the floor. When the ramp body is rotated about the pivot bar and the detent is aligned with the bore, the detent engages the bore in the bore's selected angular orientation and holds the ramp body in the stowed position.