The first set I had clunked when I went from neutral to first gear. The second set clunked when I went from neutral to reverse. Both sets clunked when would let the rpms go up in a gear and suddenly let off the gas. I don't blame this on the Leader Gears at all....most likely a poor setting of backlash upon setup. Anyone else have this problem? Its like there is too much play between the acceleration side and the coast side of the gears. I think I'll go with Greg D. and Russ Sylvis and give this one more try. thanks for the good input. I wonder if polishing the gear set first would help ?