Snow Blowers

I have a Husqvarna Snow Blower 10530SBE. It has worked fairly well in the past, but I now have a problem with the auger. (The engine starts and runs fine.) The auger control shaft has a roller arm which is meant to put pressure on the impeller arm, thereby engaging the auger. (I think, per the owner's manual drawings.) With mine right now, the roller seems to "miss" the impeller arm, or if it does hit it, it slips past it upon the first squeeze of the trigger. The auger shaft does not seem to be bent. Any ideas as to what might be needed? It is too large a unit to be loaded into my small SUV for easy check by a dealer. Thanks.