Abstract: An automotive seat assembly having a J-lock safety device which interlocks a rear seat entry track mechanism during high load situations. The entry track mechanism comprises a lower track and an upper track movably supported by the lower track for providing fore and aft movement of the seat assembly along a longitudinal axis. A downwardly facing first hook is attached to the lower track and has a J-shape with a long leg and a short leg interconnected by a bottom. An upwardly facing second hook is attached to the upper track and has a J-shape with a long leg and a short leg interconnected by a bottom. The short legs are in mechanically overlapping relationship for limiting relative movement of the tracks in a direction transverse to the longitudinal axis.