origanl heidelberg diecutter

having a prob with are diecutter sbz 22388 21 1/4 * 30 1/4.we can not get the hand wheel to move to unlock the lead edge of the impression cylnder jacket .They broke the pin in the wheel trying to get it to move .We have replaced the pin but i know if we try to force it will just break again.Just wondering if anyone would know what else could be causing the wheel to stick so hard.