Does your machine have the optional dust plate installed above the cylinderIJ The owners manual tells you to remove this apparatis when doing corn. I have a tx66 that doesn't have one of these plates installed, and I just purchased a tx68 that has one of these installed in it. We used the 68 at the finish of corn harvest, but we adjusted the spring loaded plate for maximum clearance and had no problems with leaving this dust shield in while doing corn! The principle of this dust plate is to adjust it as close to the rotating cylinder as possible and it will create a vacuum and draw the dust up into the machine through the feeder house. Since I haven't run this tx68 with the dust shield in small grains or soybeans, I can't honestly tell you how good it will work. Hope this helps you.