Outer Limits 4x4 Board

Please excuse my general lack of mechanical knowledge:

What does it mean when you put your foot on the clutch (in neutral) and the RPM goes up by 50-100?

I've also noticed it's making some noise (gentle scraping sort of sound) when clutch is out (in neutral)

I know that when clutches start making noises it's not usually good.

I dont think the gear oil has been changed in a while (it was just serviced, but not sure if they did it or not)

Any advice??

its a common problem with sierras, noisy throw out bearing, its either stuffed or dry, so if ya ever pull out the gear box replace it, as for ur clutch it souns like it needs adjusting.