Last year, down, wet rice. Quite a few of them, after they broke loose, they went on top of the screens, then out the spreader or chopper (even worse!). I can't tell you how they fixed it because I don't remember a clear cut solution. They may have added another bolt in the grates, but don't remember for sure.
Two combines First one fell out at 40 hours The second combines grate fell out at 85 hours AND then the first one lost the second grate in line at 100 hours. We think it was loose bolts but now they are LOTS tight.