Abstract: A vehicle having a suspension system that supports a vehicle frame has a suspension interlock for governing the distance that the suspension system may move away from the frame during a vehicular rear impact event, thereby channeling impact forces through the suspension system and into the vehicle frame. A flexible member attaches to the vehicle frame and to the suspension system and acts as a tether to maintain the position of the suspension system relative to the frame. Alternatively, the suspension interlock may be a u-shaped bar mounted to the vehicular frame that interacts with a pin that is mounted to the suspension system. The pin resides within the confines of the u-shaped bar to maintain the position of the suspension system relative to the frame. Alternatively, a hooked plate may be used instead of a pin.