Tranny or Clutch
In your case though you say the sound is there all the time, in my case the sound goes away if the clutch pedal is depressed.
it could be TO or pilot bearing so you won't know until you pull the tranny. If you want to see if the clutch is disengaging all the way, jack up rear end, start car, put in gear and hold clutch all the way oin...do tires move?...if yes you have a dragging clutch likely cause is weak hydraulics
CamarOkid...the noise in neutral (marbles in a can) with clutch out but goes away when you push in the clutch...normal





