I have a Frigidaire Heavy Duty dryer. After running for at least 2-3 minutes, it starts sqeaking and squealing consistently. First as a on, off as I something is rubbbing in a certani part of the turn, then contantly and high pitched. Its so loud I can hear it upstairs with the bathroom door shut!

If it isn't a belt what can I do?

You need to tear it down and clean it out well and lubricate the support rollers with white lithium grease. If you don't you will have even more problems. I recommend getting a new belt while you have it apart. Here are some links to look at for instructions:
http://www.electrical-forensics.com/Dryer/ElectricClothesDryers.html
http://fixitnow.com/wp/2010/10/09/whirlpool-dryer-model-le5800xsw3-wiring-diagram/
http://www.youtube.com/watch?v=MMP7BW1lLs4 to see how. Also: http://www.youtube.com/watch?v=iBiRw-KElC4 ; http://www.youtube.com/watch?v=yFTZGgVisCI
http://www.youtube.com/watch?v=iBiRw-KElC4
It's an easy job; just make sure to remove all air ducts and wash out the ducts because the lint builds up like concrete. DrTom4444