355 gearbox noise

I have a little annoying rattle noise coming out of the gearbox, the clutch was just replaced about 3 weeks ago including a new t/o bearing. I'm not sure if this is normal or not since I don't remember this sound before the clutch service. The sound only occurs on idle (1000RPM) when engine is worm. The car runs very smoothly and pulls very strongly at all gears otherwise.

Any suggestions will be appreciated