I had been cutting some extremely tall grass with my Bad Boy without any problems. When I finished, I stopped, disengaged the blades and there was a loud screeching/clunking noise as the blades came to a stop. Shut it off - have cleaned everything - no obstructions - looks like all is intact - still makes the same noise but only while disengaging the blades. I've lowered the throttle first and the disengagement button slowly - no change. Seems to mow fine - any suggestions?