This bolt under the sheave needs to be backed out completely so you can get the cable seated properly in the sheave. Once the cable is set, run it back it to prevent the cable from falling out when the lift is fully lowered. The 'instructions' mention a jam nut on this bolt, but I'll be damned if I can find one. I just snugged up the bolt in place, but may visit the hardware store and pick up some jam nuts later.