My tranny makes noise while i'm at idle with my foot off of the clutch. Is that the throwout bearing or the input shaft bearing? I think I read a post a little while ago about this. When I push the clutch down the noise stops. Is this a bad thing and does it need to be replaced with a new clutch right away?

 

im bout 50% sure its the TO bearing. How many miles? 1st clutch? TO ever changed? Tranny Condition? Oil?

 

Usually it's the throwout bearing, unless your clutch is toast and one of the springs broke off of the disc, or if your pressure plate is toast. But if it's a new setup, then the throwout bearing maybe bad or not installed correctly.

 

The car has 70k miles on it now. It has an aftermarket clutch in it also.

 

Have you actually localized the sound to that area? I mean a "noise at idle" is pretty vague, and could be a lot of different things. Also, your T.O. bearing would have to be in pretty bad shape to make a noise with the clutch engaged (i.e. your foot off the pedal) because there's no stress on the throwout until you try to disengage the clutch. I would definitely be more suspicious of the input shaft bearing if as you say the sound goes away when you disengage the clutch.

 

My car is at the dealership right now getting the tranny rebuilt under warranty. I talked to the mechanic that's working on my car and he said that it was the throwout bearing.

 

sounds like input shaft bearing to me. Reason, throwout bearing would be making noise when you press the clutch in. input shaft makes noise with it out, even in neutral.