[Fiddybux]

None of the above!

Mesh is tight enough and loose enough if you know what I mean...very slight wobble in the spur against the pinion....as it should be. You know when its too tight because of the noise anyway, and it was fine by my standards and no-one else commented on the noise until it failed today.

The mesh was equal all the way around as well. This is always checked...even on a simple 2WD setup.

Maybe for some reason the motor moved slightly under strain...perhaps after a jump...or on acceleration? Who knows. It was certainly checked and tight enough before I started.