Gear box Noise when clutch released

this started yesterday put the disco in first gear let the clutch out there is a grinding noise from the gear box for a second once the disco is moving there is no noise. Drives normally. If i stop the car put the handbrake on let the clutch out untill it starts to bite the noise is there sounds like cogs rattling. (1999 TD5)

Fubared clutch release bearing probably

if its a td5,more than likely the duelmass flywheel,they tend to make wierd noises,but when they collapse u know about it,the bearings collapse inside and the center comes away from the outer where the clutch is held! or as the post above suggests may be the thrust bearing!

If it's the clutch release bearing the noise normally goes away after initial starting (at least mine does). Think it's an ambient temperature related thing due to not enough and cold grease in the bearing. Does'nt happen on mine in the summer, been like it for nearly five years.