how do i fix my hoover vacuum cleaner?

i have the simple hoover. no extras, just a hoover upright with a removable tool rack... i bought it for a great price and im wondering if that was a bad idea. i was vacuuming one day and i dont know if i sucked something up but, all of a sudden the motor became 10 times louder. it is still sucking things up perfectly fine but the noise is unbearable. i live on the top floor of my building and people on the first floor (three flights down) say they can hear it. its so loud i cant even have the thing turned on for more than thiry seconds. is it repairable and worth it ? or should i just junk it and buy a new one for 50 bucks?