[chevyguyase]

If your transmission is in neutral and the engine is running with the clutch out your pilot bearing is not turning because your input shaft is locked to the crankshaft 1 to 1. If you put your truck in gear and push your clutch in then the pilot bearing is turning. I'm thinking fork, throw out bearing. Check it as soon as you can because if your throw out bearing locks up it will spin on your bearing retainer and ruin it (The part your throw out bearing slides on) . Lube the fork pivot points, dry pivot points can cause noises.