whining noise louder faster you go '02 4.7 1500

[WolfeRam]

does not make the sound when rev engine up in parked so it's something only gets louder the faster you go. i can't tell exactly where it's coming from but it sounds kind of like all around vehicle which makes me think from the rear axle or directly under the center maybe the transfer case bearing? or the steering column?

i know enough only from one i've watched in youtube stuff. i'm no mechanic so i'll have to take it in somewhere but would like to point them the right direction so they don't tear entire vehicle apart.

TIA

 

[Ian_Olivas]

Sounds similar to something I had a few years ago. If it's like a roaring noise and gets louder when you let off the gas it's from the differential and the pinion bearing is bad or that pinion gear is loose and falling out cause the nut backed off over time.
You mentioned a transfer case so im assuming you have 4x4 and couldn't tell where it was coming from. I was able to easily tell it was the rear but maybe yours is from the front?

 

[Ole Buck]

Is it a high-pitched whine? if so like stated above its most likely a pinion bearing.

 

[WolfeRam]

it is more high pitched than low pitch. almost sounded like tires first time i heard it but realized it wasn't tires. i bought truck from another guy he said he heard it for entire year he drove it and never had it checked out.

sounds like the first guesses are pinion bearing. how much does that usually cost to get fixed?

any other common things that go bad that would make that noise i should get checked out?

thanks guys