20-11-2020, 11:18 PM
The fact that the noise is present in the intermediate gears indeed points at the layshaft as this only transmits power when not in top gear. The problem may be layshaft bearings, allowing the gears to run incorrectly meshed or maybe the box has been assembled with "odd" constant mesh gears at some time in the past?
First thing to check however is that the box has the requisite amount of correct (SAE 30 or 20W50) oil.
First thing to check however is that the box has the requisite amount of correct (SAE 30 or 20W50) oil.