I have an '89 Mustang LX 5.0, and on the passenger's seat, the lever in the front of the seat (not the side lever) moves freely left and right. Sometimes when I stop, the seat moves foward and the passenger jemps forward. Sounds funny, but this is very dangerous. Is this just a spring missing, since it doesn't lock in place? If yes, what size spring? I'd imagine I can get them at the local hardware store, or Home Depot/Lowe's, no?