Originally Posted by wpoll

To add to what the others have said, you have to get the retaining bolt partially installed, so the end of the thread is sitting flush with the outer side of the new carrier (flush with the end of the plastic retainer sleeve). Then press the lock carrier into place and hold it hard against the door seal while turning the retaining screw.

What some folk don't realise is that the carrier hole is threaded too and so you need to "set" the distance between the two parts before winding in the retaining screw; once they are both engaged in the threads no amount of tightening will alter the distance between them. That's why the lock carrier ends up not sitting flush.