There is a pin that drives the incline auger at the bottom of the flighting drive. We had the pin come out but it would still bring the corn into the tank with just the friction of the joint. When the corn got above the incline auger and had to push the grain up it would slip, then plug the auger and the slip clutch would start. Check if you can turn the incline auger in the tank by hand with the machine not running. If you can turn it a little the pin is out at the bottom.