My spare carrier came to me with a giant wing nut. I think I had to drill out the bolt to get it serviceable to use again. Easy enough to weld a new thread section on. I don't recall the exact size, but I don't think it's larger than 1/2-13. That nylon nut is a good idea, as it's not going to rust on to the bolt and could be loosened more easily with fingers than a steel wing nut. I may have to look into that.
