4wd loud when engaged

My 4wd is louder then I'm use to on my other 4wd trucks. There is a significant noise difference between 2wd and 4wd coming from the front end. It sound something like a growling noise. I know somepeople have said then can hear a rotational noise when driving. This is diferent then that. It only happens in 4wd. Any help would be appreciated.

What year is your truck? I have what sounds like the exact same thing on my 99 New body style Z71 ext cab. I have the manual shift 4WD and when shifting from 2 wheel to 4 wheel the front end has a really noticable growling sound. The growling sound does not instantly go away when shifting back to 2 wheel either, it usually gradually fades away back to normal. I haven't crawled underneath it yet to poke around, I am only guessing that it is either a U-joint or perhaps the CV shaft. I am hoping that is all that it is and not something inside the transfer case. Anyone else have any ideas or know what this is?

I have a 02 1500 with the auto trac 4wd. Your description of the noise is exactly what mine is doing. I have it in the dealer right now and I will let you know what they find.

thanks. Mine being a 99 with 110K is no longer on warranty.

My dealership just told me that I needed carrier bearings replaced. Does this sound normal to anyone. Just seeing if this is reasonable or not. It is is under warranty, just not sure exactly what a carrier bearing is for the front diferential.

I have a 99 new body style also, Mine was the inside drivers side bearing that is out in the front diff. Go under your truck and see if you can move the axle shaft up and down that comes out of the front diff. My dealer told me that it would cost $600. I went to a junk yard and got a used one for $300.

The front differential is not "set up" per say like a typical rearend.The rearend on your truck are 100%shimable, the pinion and the carrier. The frontend is not. A lot of the frontends on the IFS Chevys, GMCs are loud when locked in to 4-wheel drive. It is luck of the draw. Out of 5 trucks 4 of them will be loud and the 5th will be fine.

I have 2004 Sierra with autotrack and experiencing the same problem.

When I switch to 4wd a distinct growling appears and as soon as I put it back in 2wd it goes away. This summer I used the 4wd and never noticed this noise it showed up in the fall and with all this snow I've been using it alot and it is starting to bother me.

I have also noticed in 2wd when I take off from a stop I hear and feel a clunk in the rear, it sounds like a worn U joint.

Well I guess i'll bring her in for a check, I'll let you know what they say.