transmission noise on 1997 Nissan Pickup (D21)

1997 Nissan Pickup, 5-speed. Roaring sound when clutch is pressed in. Stops when clutch is released. Mechanic syas he changed all bearings. Any ideas? Thanks.

Asked by for the 1997 Nissan Pickup (D21)
I have seen the pilot bearing cause this noise sometimes only when you first start the engine in the morning, perhaps a bad clutch pressure plate release bearing.