On closer listening the loudest sound seems to come from where the bottom arm connects to the arm coming from the motor. I can't wiggle anything but perhaps there is wear in the pivot point. I think I'm going to get brave and open the gear box and see what if anything is going on in there. Supposed to be a way to set the counter weights, if they are out of wack. I feel this is my best chance to quiet the beast at least a little.