Patrick, sorry to hear the trans gremlin has followed you. Not really sure what's going on with the later roadster transmissions. They seem to end up with bent shift forks from what I'm reading. Not sure if they're getting knackered during assembly by some ham handed limey(
) or what. As you may know I had my gears backcut and the shaft grooves widened to accept heavy duty circlips. That should take most of the side loading off the shift forks and circlips. I'm reluctant to advice anyone else of doing this until I have some long term data. There has been talk of removing the surface hardening when backcutting. Whether this shortens the life span of the gears is yet to be seen. When you say knocking, does it feel like the gears are going in and out of mesh ? Like the side engagement dogs are slipping past each other ?