The race/extreme mode is designed just for that; race/extreme. Will tear stuff up, especially trannys. You really shouldn't get out of tow mode.....ever. I know that being able to drive 80mph up a tree is cool, but you're paying the price at $1900-2100 a pop....
Are you sure the whine is the trans? Hard to believe you can hear a trans whine over the stroke racket.......