The enclosed portion of my chicken tractor has a drawbridge-style door that I close at night by pulling it up by a chain. The trouble is, it get shavings stuck around the bottom and then it won't close all the way. I have been just pulling it pretty hard to get it to close, but that backfired recently when it just broke right off. Since then we've just had to move it out of the way every morning and prop it up at night, which has been ok so far (the run is pretty secure, but annoying and far from ideal. I can't easily reach an and brush it off, and if snow gets in there and freezes to the shavings it's even more difficult. Is there some way we can prevent this from happenning again when we reattach the door?