Hey guys im having this rear end noise in my truck that sounds like a howl or whirling noise. its not the wheel bearings. I uses a thesescope a wile back and i could not pin point where the noise was coming from, so i assumed it was the drive shaft. Could someone tell me the diffrence between carrier and pinion bearings i have no idea about any of em. the noise is there as long as the truck is moving. It can be off, in neutral, or in drive and it still makes the noise.

Thanks =)

 

Read here
http://www.ringpinion.com/FAQ.aspx
There is some good info in this section
Hope it helps