I have two 496 disks that the pins that hold the tongue to the frame, keep falling out. I think they're 1 1/8" or 1 1/4" diameter and about 4" long. They're just held in place by a cotter pin or hair pin. I'd feel safer with something a little longer and something stronger than a hair pin. I lost the originals and currently have pull pins in their place. What should I use, large pull pin, hardened bolt, or something else?