Am I right in thinking that there are 2 points that can cause play.
1. Sector shaft adjustment with the screw.
2. Preload on the input shaft bearing.
Trouble is I cannot find how to set the preload on 2 above. Using matchmarks will only set the preload to what it was when the box was new. Due to bedding in I would think a new setting would be required.
Just very interested, don't need to go there yet.