John Deere 318 50-inch mower deck: Does anybody have a method for keeping the grass clippings and dirt from accumulating in the mower deck where the deck belt is located? I've tried thin foam gasketing under the shields or tape over the shields' to no avail. I think the problem is primarily around the opening to the pulley shaft, but I can't envision a way to place a collar or gasket to somewhat seal that hole. The debris gets wet and forms manure in there sometimes and causes a lot of rust. I've overcome the rust by using POR15, but I'd like to keep the crap from crowding the belts and wadding in there altogether.