Help, the fan blower on my furnace is noisy. I turned it off and manually spun the fan... it moved smoothly. Any suggestions?

Boy, I must put up with an awful lot, maybe cause I gave up asking hubby to fix anything and it stays on a waiting list, unless I can fix it (and I do most everything around here). My furnace blower sounds like a cyclone hitting when it comes up the pipes. I have grown accustomed to it, and if I didn't here that roar I would worry the furnace wasn't working! Where is Tom when you need him anyway ! TOM, YOU OUT THERE ?

Oh, and put up with low water in my toilet. I just live for Tom's thoughts on these things, and then I get out my screwdriver.