Ok, for a daily driver, I have a '98 GMC Z71 with 102000 on the clock......
As said above, I have a roaring noise that is definetly coming from the front end. It almost sounds like my tires, but I can feel it in my pedals and my steering wheel. The sound changes slightly when I turn my wheels slightly. It sounded like it was coming more from the passenger side, so I replaced the passenger hub day before yesterday. I test drove it and the noise was still there.I checked the fluid in my transfer case last night and I couldn't touch any at all with my finger. I added some Dexron III and filled it up, but the noise is still there, loud as ever. Could my transfer case be perma-screwed or could it be something else. Neither of my axles have broken joint covers on them, so I can't see the sound coming from there. 4 wheel drive still works normally for now. I don't want to have to replace my transfer case, but......
Any advice would be greatly appreciated.

 

Couple of things to check:

1) Is the sound your clutch fan in permanent lockup mode? They can be really loud.

2) If the sound changes when you turn the wheel, have you checked your power steering pump?

If the noise is only present when the truck is moving, I would also look to see if there could be a problem with sticking brake calipers or rubbing suspension parts.

 

1) fan clutch is still working
2)It does only make the sound when It's rolling. As far as turning, I actually meant that If I turn the wheel slightly one way or another when moving (as in changing lanes) the sound will go away slightly or increase slightly at times (definetly a noticable change though). The sound does change the faster or slower I go though.

I checked for anything rubbing already, and I cant see anything. I will check my brake calipers though.
Thanks

 

Sounds like your wheel bearings but, I've also experienced this from damaged C.V. shafts.

 

I think it is the wheel bearing. Took it to a transmission shop and the guy drove it and said it was not the transfer case but the passenger wheel bearing.....which is what I thought it was too and the one that I just replaced. Guess I screwed up somewhere. Hope Oreillys honors there lifetime part guarnatee cause I'll be taking it back tonight for a new one.

 

Make sure it isnt the left front. Sometimes when doing the old weave from side to side
manuever to determine which side it is, it will trick you.