By "propeller" he might be referring to one of the augers. But who knows, a picture would certainly help.
Please supply a photo, I cannot decipher your description.
If the manal IDs it then follow the manual. I can't see any mention of it in the parts diagrams available online for that blower. Only for the impeller fan mounting bolt.No, it’s on the fin itself. Only on one though. Manual talks about torque it to a certain amount.