My buddy had one of these and it ran fine for like two weeks before the gears started grinding. He said it sounded totally normal until he actually tried to put a load on it, then it just started slipping like crazy. Got a used replacement from a guy on Facebook and that one had a cracked gear hidden behind the housing you couldn't even see without taking it apart. I read somewhere that the plastic gears in these are basically made of butter after they get some heat cycles in them. Would definitely run it under a load for a solid 10-15 minutes before trusting it lol.