Can somebody help me on Harry Potter for Wii!?!?

On the part where you go around messing the school up, when you take the gears out of the clock with wingardium leviosa, I can't get the gears to go up on the ledge. But I can get the little one up. When I finally get the gears up beside the ledge and try to move it over, it falls or goes lower. HELP!