I haven't noticed the noise much yesterday or today. But, the weather has been warmer. This is something I'm going to watch very carefully, and I'll also have to check my level.

 

Mine howled in any weather. It was worst between 40-60mph. It did it with foot on the gas, or foot off, especially loud at about 45mph.

 

Took the truck into the dealer last week and had the shop foreman take it for a test drive with me to diagnose the wind noise at highway speed in a cross-wind problem.
Instead he picked up the sound of the rear end diff howl and Friday and they rebuilt the rear diff under warranty. I had read about pinion gear problems...looks like mine was one.
Surprise surprise... he also gave the OK to replace the door weatherstripping as the early build 03's have a different door seal than the newer ones. Wind noise now gone. Rear end howl now gone too....if I could only get the kids to stop howling in the back seat I'd be real happy!

 

Mine howls too. Only when the A/C is on, at the begining of acceleration, then it tapers off. Definatley (sp) ? under the hood.

 

I have had the 20mph ghoastly howl, 19,000mi and the pinion seal started spraying oil, The dealer just replaced all the bearings and set up the rear diff for me... I still get a slight howl when cold but I think it is better and no leak or vibration . Happy for now