Gearbox Vibration

[Birds]

Try revving the engine in neutral with both clutch pedal pushed and clutch pedal not pushed. If it goes away with clutch pedal pushed then I would say it's an input shaft resonance - could be a bearing, could be the shaft itself, but most likely the former. If it doesn't go away when clutch pedal is pushed then it could be:

A. The spigot bush/bearing

B. Thrust bearing sitting against pressure plate in a resting state (rare)

C. Pressure plate resonance

D. The engine bottom end and resonating through the gearbox

[Nee-san]

Ill lock in A eddie !