4WD Vibration

Everytime I have my 99 Silverado in 4W Hi, I get frontend noise and vibration around 40 mph. I have had a dealer look at this and they tell me it's normal. Doesn't seem right, so I ask, normal?

Thanks

Your first question about locking sounds to be normal to an extent when you turn there's going to be some binding in 4wd. As to the vibration it could be any number of things. Mine was bad transfer case bearings which were found and replaced by the dealership under warranty. Do a search of posts about 4wd vibration.
Jeb

Thanks for the reply.

I don't have any front end vibration when I'm in 4WD at any speed. I'll have to ask a dealer if that's abnormal.

TXAGG05...I have a noise coming from my transfer case when I run my truck in 4WD Hi. The noise stops when I apply a little pressure to my 4wd shift lever. Is this similar to the problem you had?

Thats usually normal also. I'm not personally fimiliar with a chevy's transfer case, but I know ford's do the same thing.. at least the 2 I had did.

My truck has the autotrac x-case so there's no lever to rattle. My problem was better described as more of a whining or a dragging feeling and sound. It was cured with the new bearing races. My truck still makes noise that I would consider normal 4wd operation. This noise is made or amplified by the more aggressive tread pattern of my tires. I checked my tire pressure a couple days ago and realized that I was running pressure much below the tire mfg. reccomended specs. I haven't even thought to engage my 4wd and see if this has quieted the 4hi operation any. If you want more info about my problem search my posts back to when I had the problem and when I fixed it.
Jeb
P.S. I consider my 4wd to be ok if it doesn't make any strange noises on loose sand. My road between blinds at our duck property is a sandy road and when I had the problem with the truck it would make noise on the sand road as if something was scuffing the front driveshaft everytime it turned.