What year is your snow blower ? I too have a Allied/Farm King snow blower and it too has the three blade fan - hhhmmmmm. I have a copy of my manual I can send via email if it would be any help. It is a 1989 73" wide blower.
Have you opened up the gearbox at all ? Is your gearbox an enclosed one - if so you should have oil inside. There are level plugs/vents and I opened my gearbox up and cleaned it out when I first got the blower. The gearbox was dry, so opening it up to check paid dividends for me.
I have attached a picture of my blower - I added wings to make the effective cut wider (works well).
If you need a copy of my manual shoot me a PM.
Hi, I just picked up the Allied 73" snow blower pictured below. Looks alot like yours. I know this is an old thread but if you are willing... I would love to have the electronic copy of the manual e-mailed.