I put on a new jack in the spring and replaced some loose bolts holding other jacks on. My AS is by no means in bad shape (nor perfect!) but the holes holding the jacks on were so corroded that no 1/4" fastner was going to hold the jack on. There's some other discussions here on the forums about J bolts. I couldn't find anyone locally that carried them, so I cut some 1/4" all-thread to about 3" long, then bend the top 1.5" of it into a curve. I drilled the holes in the frame to 3/8". Then, you can slip the homemade bolts up into the frame rail and you're left with a stud (loosely) sticking out. When you start cranking on the nut, the part up in the frame will eventually stop against the frame and you can torque it down.