I got my 460 Rancher stuck in a tree the other day in a bad position (completely sideways with the engine weighing down the 24" bar). After using a second saw to fell the tree I got my bar free, but it had a slight but noticeable bend in one area. I thought it could still be useable, so I reassembled everything and it worked, until all of a sudden the chain came off. When I looked down, I noticed that one of the bar nuts had come free, which had loosened the clutch cover. After reassembling everything, including synching the nuts down tighter, I tried again and the same thing happened. I decided that it must be the bar and bought a new bar and replaced the chain. I go outside this morning thinking I'd figured it all out, and the same thing happened. Upon closer inspection, I noticed minor damage to the chain brake teeth on the handle end (see picture). I'm wondering if that is my issue or if I should consider locking nuts. Every time, the same thing occurred; one nut wiggled its way off and then the chain came off.