Repairing Ice Maker Shut Off Arm?

I have an inside the freezer icemaker that was doing fine and now the inside part of the shut off arm keeps falling out of it's socket or whatever it's attached to. Anyone have any ideas about this? I am wondering if there is a piece of the module I could replace or is there a spring in it? I am having a very hard time finding good information about repairing this outside of buying a new icemaker. I know this can be fixed somehow. I was even thinking of putting something like a cotter pin on it to keep it in place, but still loose enough to go up and down. Any input appreciated!