I have an Ariens ST5520 snowblower; 5 hp engine, 20 inch wide scoop.

My experience has been that when the auger belt is loose or stretched, the machine will only throw the snow a few feet, like 4 or 5 feet. The auger and impeller will appear to turn normally when they're not under any load, but as soon as you try to throw any snow, it'll only throw it a couple of feet or so.

I would take the small cover off between the engine and the scoop and feel the tension in the belt that turns the front pulley (the one that turns the shaft that turns the impeller and the pinion gear (that turns the auger). If it's loose, just tighten the belt tension and see if it works better.

If tightening the belt helps a lot, then I'd plug through till spring by just tightening the belt, and then replace that belt in the spring. You can do that yourself, but you need to follow the instructions in the Owner's Manual. If you don't have that owner's manual, you should be able to download it from Ariens web site.

If the machine isn't throwing the snow AT ALL, even after tightening the belt, then I would suspect that the shear pins or set screws that hold the impeller onto the shaft that turns the pinion gear (that turns the auger) are broken or loose, respectively. Maybe get in there with a bright light and see if you can tell what holds the impeller to that shaft, and if it's broken or loose.