My gearbox often crunches when changing down from 3rd to second gear. I believe it's accidentally hitting reverse as reverse and 2nd are very close when it comes to selcting. I have checked the gear lever mount plate and it is fitted correctly with the "ski jump" at the drivers side and the square lip at the passenger side. I've also tried moving the plates position still to no avail.

The sterling build manual (
mentions this very problem and the solution given is to adjust a set screw just above the ball of the selector but mine doesn't have this feature?

Any suggestions?