I have a 2001 Toyota Avalon XL, the transmission or the gear-box make a whisper sound when I’m driving between 28-40 miles/hour. the whisper goes away when my speed exceeds 40 or under 28, do you guys think the transmission is getting bad, ???? Please help

is it under warranty?

No way, its a toyota, sounds like just a little bearing noise, or something, it will last 500000 miles