2002 Challenger whistling in the wind

[Canlab]

I have a 2002 Challenger with a 240 EFI Merc. At certain RPMs I hear a whistling or whining noise coming from the back. It's really hard to pinpoint. Speed up a little, it goes away. Slow down to idle it goes away. It runs and starts good and there is no loss in power. I recently serviced and changed the oils in the bottom end and everything looks really good.

Anybody else have this problem?

 

[Dr Honda]

Whistling, and whining are 2 totally different sounds. So... it's hard to even start with this.

A whining sound could be water in the gear case. (bad)

A whistling sound could be anything that air is passing. (probably nothing)