I'm sure that mavalgear is not the only source for rebuilt boxes. The problem is, as evidenced by this thread, many of these rebuilders give no special attention to "tightening up" the boxes.

There is no adjustment to do so. I have examined one of these boxes and I believe that I can tighten them up properly. My exploration has been with the 123 box which is really bad about loosening up and cannot be tightened with the adjustment.

Have a great day,