Any Bad Auto Trac push button 4x4's?

More questions.
My 4x4 makes tons of noise when I'm in 4-WD. I have the Auto-Trac pushbutton on the dash along with the 2-wheel Hi, 4-wheel Hi, & 4-wheel Lo switches. And I have two questions.
1. What might be the cause of the noisy front end? Mechanics at the local Chevy garage say that some make the noise and some don't. I don't know how true that is, but I can say that it seems to work okay, it just makes a loud noise while it is in 4WD. In fact, when it is in Auto 4WD it makes the noise and I think that it is always engaged rather than only engaging if it needs to be in 4WD.
2. Has anyone ever heard of the Auto Trac switches going bad? The same mechanic told me that he prefers the manual floor gear lever over the on-the-dash switches, saying the floor lever is more reliable. I'm not a mechanic, so I have to rely on others in any case.

There was a question almost similiar to this one here not long ago. You asked if anyone had their switch go bad. I did. My 99 Z Service 4 WD light came on one day, so I tried to diagnose the problem myself and put it into 4wd, well it wouldnt come out so I called the Gm dealer and they told me that the switches in those(I dont know if me meant 99, or auto-trac) trucks went bad kind of regular. He installed a new one and I havent had any problems since. I can say one thing for the Auto-4wd part though, my friend had a 00 2500 and his transfer-case went to hell after he used the Auto function a few times. Even when locked in 4-lo it wouldnt move the front tires. What the GM place found is that the clutches in the transfer-case broke into pieces, and it ended up being cheaper for him to trade it in, broken, on a 03 2500 HD rather than fix it.
My truck makes a slight amount of noise when locked in, but nothing that just sounds horrible, and mine works fine.

Mine started making noise recently in 4-hi, and more than just the noise of the front running gear. When I put it in Auto-4wd I can isolate the noise that it makes in 4hi......My truck did not make this noise when it was new...and besides,..isn't auto-4wd mean that the transfer case is not engaged?..so it should make any noise anyway unless its slipping. I took mine to the dealership a few weeks ago and they gave me the "normal" seal of approval. I'm going to take it to the dealership in Houston when I go visit my parents for the holidays. For some reason, that dealer never gives me the run around.
Please do tell if you hear something about it before I do.
Jeb

Also, my best friend's truck seems to be suffering from the service 4wd/4wd switch problem.

I've seen lots of bad front pinion bearings lately in the cold. You might want to get the front diff serviced and check for metal on the magnetic drain plug. Also...lots of switch failures, but also some of the position sensors in the encoder motor on the transfer case have gone bad, depending on the diagnostic trouble code.