Since you did not provide a model of the unit, here are some basic ideas for this repair.
clean the threads and retaining bolt with a cleaner, Brake Clean, starting fluid, to clean off any oil. then apply Red Loctite to the threads, tighten until rope will still retract. wait 12 hours for locktite to dry.
#2 is there room for a spacer washer between the bolt and the housing? this would allow you to tighten and give a little space. \