[jimmiprice]

I had the same problem mate, took me ages to get to the bottom of it. Mine sounded like noise from the pinion - spur mesh and no matter how i set the mesh it still was there it sounded like i had installed the transmission from a mid 90's predator !
I tried 3 different 83t spur gears and found that they where out of round, there was always a tight spot in one area of the spur.
I swapped to an 81t and at the same time put some lube on the two metal gears that run on the end of the layshaft and the noise went away. Its now as quiet as my cat aero.