2006 2500hd growl problem, help please

Hello all. I am new to this forum, and recently purchased a 2006 2500HD with the 6.0L. I am a decent mechanic, but am new to 4wd, and could use some help.

In 2wd mode, the truck makes a growling noise. I thought it was a wheel bearing, but it only makes the noise in 2wd. It does it around 10+mph. Turning to the right makes the noise a bit louder, turning to the left makes it quieter. It also sounds like it is coming from the front of the truck.

Any help is appreciated, thanks, Rodney.