Well, all that I've read says that the steel gear set usually makes some more noise than the fiber (maybe that's why they made the fiber ones, to cut down the noise?), so I expected there to be some change in the way the engine sounded. Makes sense to me that changing the materials of something prominent that spins at high speed would result in an audible alteration.... But it does nag at me a little bit, so when I get a chance I'm going to pull the cover and take a look and make sure everything looks like it's supposed to...