The Rattle Controversy

All right guys, this is a controversy that has separate my friends in two groups " Clutch vs Transmission", and this is the why, my 2005, 4x4 single cab manual transmission Tacoma has started to make a Rattle while is in neutral with the engine running and the car park still. So I push the clutch and the noise is gone I release it and the noise is back , but something very particulate happens if I turn on the A/C, the noise gets louder. So my personal guess will be that the springs of the Clutch pressure disc have wore out, and some how the increase of rpm in the engine caused by the A/C make the pressure plate vibrates more as the reason of the increase of noise. there is this part friends of mine that agrees with me in this assumption but other part that have the idea of the cause of the noise might come from a bearing somewhere in the transmission, so the only way to make sure of the correct diagnose would be to take the transmission down for eye inspection but is expensive because any mechanic would do it for free just as part of a diagnose, so guys the 1, 000 000 dlls question would be, based in you TACOMA experiences what would your guess be???