Welcome to the forum Neil!
To be able to help you more, need to know what all is worn. The shaft that is connected to the impeller runs the auger drive. It is only held onto the impeller with a spirol pin. The impeller "floats" on the spline shaft out of the rear gear box. Unless the thrust bearings in the auger drive gearbox are wore out, or the impeller is bent, it should not be rubbing. I just rebuild the auger drive gearbox on my machine. As long as the case is not damaged beyond repair, it should be fixable. I suggest taking the augers and impeller out, (they come out as an assembly), and go from there. Lets find out why the impeller is hitting first.
