4-speed troubles

[Charger1970]

I had my 4-speed transmission rebuilt a year or so ago due to severe gear whine. The rebuild seemed to be fine since the gear whine was completely gone.

Not long after I got it installed it began making a noise, but only when the transmission was cold. It now makes this noise (now quite a loud noise)  when the transmission is cold or hot.


The noise is sort of a buzzing sound, almost as if two gears are BARELY rubbing together or a bearing is spinning inside a race.  It's easily heard inside and outside the car.  
The transmission was installed with a new clutch, throwout bearing and correct pilot bushing.
The noise only occours when the clutch is depressed and the shifter is in any gear.
There is no noise when the clutch is released.
There is no noise when the clutch is depressed and the transmission is in neutral. As soon as I shift into gear the noise quickly 'spools up'.
The transmission seems to shift just fine.

Any ideas of what it could be?  

[OttawaCharger]

If I recall correctly when you press the clutch pedal down and the noise starts up..... but disappears once u release the clutch pedal, then it's the throw out bearing.

[Charger1970]

Yes, I believe you're right. I think it's something other than the throwout bearing though. Here's a little more troubleshooting info;

The noise doesn't happen when actuating the clutch pedal with the transmission in neutral, only in gear.
The noise doesn't appear until a second or so after the clutch pedal is fully depressed, such as when I'm shifting while driving. 
The noise doesn't go away until the clutch is fully released or the transmission is shifted to neutral.
The noise will speed up with increased engine speed.

When I first start the car I depress the clutch pedal, start the engine then...maybe 10 or 15 seconds later (sometimes more, sometimes less) I get the noise. This is very frustrating.

[Cooter]

Of course, I assume it didn't have this noise BEFORE it was rebuilt?..

[six-tee-nine]

However there are some odd things with the theory you're telling us, i would start with changing the throwout bearning. It seems to have alot to do with your problem and it mingt be the easyiest to change out first.
Meaning, you would'nt want to open up your gearbox again without changing that throwout bearing fiirst.....

[Rolling_Thunder]

Well lets see...       are you using gear oil or ATF in your transmission ? 

Why as it originally rebuilt ? Problems at the time ?