Yeah, I've torn it completely apart and ordered a rebuild kit that includes the upgraded back case and for double protection a case saver insert for the pump too. Oh, also a new pump. So far, I've only found the front output shaft bearing to be noisy, as well as the clutch pack. So, new clutch, and the upgraded spring that's stamped steel vs the multi coil wave ring washer. Chain isn't any longer than the new one but it does "twist" a bit further in comparison. So, in with a new chain too. I'm really surprised I haven't found anything more disastrous! The new alloy aluminum rear case is heavier and much quieter when flicked with a fingernail. The original magnesium one sounds like a bell! Like I said, I can't find anything that would have duplicated the "rocks in a can" sound. I'm just afraid I'll rebuild it and still have that noise. Paranoia I guess.