jr

First off I have an auto so this will be a tough one. I noticed today when I was accelerating out of a toll plaza a weird whining noise. It gets louder and higher pitched as RPM's increase. When I got home I put the car in neutral and revved the engine and the noise was still there. When shifting from P-N or N-D the noise disapeers for a moment and then returns. Any ideas? I'm thinking maybe the torque convertor or gearbox, but there have been no problems with slipping or poor shift performance. I'm due for a fluid change, but I don't think thats it. I have a very slow leak at the rear main seal, maybe it's getting worse and this is the bearing noise? Any help is appreciated, TIA.