I recently had to take my transaxle apart, I had to replace the clutch, and a few other things. After I finished everything and put it back together, I took it for a test drive. It was fine for about 3 miles, then all of the sudden, it started making a semi-high pitched whirring noise. When the clutch is in, it stops, but when the clutch is out, whether its in neutral and parked, or its in gear and driving...there's a noise. And it gets higher pitched depending on the speed of the engine.
Any ideas??

 

sounds like it could be the input shaft bearing.

 

that would be my guess,shaft bearing.