A vintage machine (late 80's - early 90's) that I bought at a thrift store had a squeaky hand wheel. Someone tried to adjusts of the two drive belts and the pulley. It sewed fine other than the squeak. It's been fine since I readjusted it back to it's proper place. Maybe yours needs a little adjustment or new belt(s)?
Edited to add
I see you posted while I was typing. Hope that fixed things.
Last edited by pennycandy; 09-16-2016 at 07:20 PM.