Fork to grove clear. 10-.30mm fork width4.8-4.9mm, groove 5-5.1mm. The barrel and the tang should be close.  .10mm?? maybe. Should be almost no movement. As its a slow moving part it won't create heat.
 Is there a washer groove in the side of a gear from jumping allowing it to float too much? The list goes on for what to look for. Everything needs to be tight basically.