I would say your not meshing them tight enough. Heres the link to the hpi clutch bell
http://www3.towerhobbies.com/cgi-bin...4&I=LXCLR9&P=K /
http://www3.towerhobbies.com/cgi-bin...4&I=LXDHM0&P=K /
http://www3.towerhobbies.com/cgi-bin...4&I=LXCLR2&P=K and removing the clutch bell is pretty easy just unscrew the one screw holding it on and it should pop right off.