When I installed my clutch, the pilot bushing seemed too small to really do anything. What is it's purpose? I'm just wondering since I haven't started the car up yet, though the pedal doesn't quite feel right... I'm a little worried about this. ACT clutch BTW. Anyone? Thanks in advance.

 

The pilot bushing keeps the transmission shaft centered in the flywheel while allowing the flywheel and transmission to rotate at different speeds when necessary. It generally doesn't see a lot of force, but it is important. Conventional wisdom says it should be replaced along with the clutch, although not necessarily.