This almost sounds like mine- if I'm going, say, 60 mph, and downshift to stop at a light, clutch lever all the way in (and feeling disengaged, the motor spins freely) it'll go click, click, kachnk, kachunk, Clunk. (the last three gears being notably louder than the first two down) might be because I'm still going a little too fast for those gears?