I have a 02 Trailblazer with I6 and automatic tranny with 98xxx miles. When the vehicle is cold I have a whining sound (kind of like a fan rubbing up against something which sounds like it is coming from the Tranny) that starts just before shift and last through the shift. As the vehicle warms up the sound gets shorter until it is completely gone. I have a friend who is a gm tech that thinks it is the TCC solenoid. Any other ideas or things to check? Thanks.