2003 chevy 2500hd grinding noise front end

[jakebe]

I have a 2003 chevy 2500hd with the 6.0. For a couple years now I've had 4wd engage disengage issues. It just sticks a little. I've got a weird noise though that I can't find any info on. It sounds like gears grinding in the front end. It only happens when the front right tire is trying to be pushed up a small incline or out of a dip. It sounds like a manual transmission that is just grinding gears instead of going in. It doesn't matter if 4wd is in or not. I know the front right wheel bearing is starting to go bad but I don't know if that's related. 

[richard wysong]

Make sure you transfer case is in 2wd by spinning the front driveshaft by hand, it should turn easily. If it doesn't then either the TC is in 4wd or the axle actuator is engaged. The actuators get get sticky due to corrosion around the threads. If that all checks out it's time to pull the axle actuator housing and check for smooth operation of the mechanism, There is a spring in there that may be broken

[jakebe]

I tried spinning the driveshaft with the truck in park. No luck. It's locked it somewhere. When I put it in and out of 4wd I can hear something  moving in there, but I can't tell where exactly. Is it best to start with the transfer case or the axle/differential? It definitely comes in and out of 4wd because I use it fairly often where I'm at. I'm assuming the front end is locked then? 

Edited May 6 by jakebe

[richard wysong]

Jack it up and see if you can turn the shaft with the wheels off the ground, If you can the problem is in the axle, if not it is the TC

[jakebe]

In 4wd with the front end off the ground, both front axles are locked together and turn, but they do that in park. The back is not off the ground. That doesn't seem right. What next?

Edited May 23 by jakebe

[davester]

They turn how?  If 4wd is engaged, and the front wheels are off the ground, you should not be able to turn the front driveshaft, and spinning one front wheel, should result in the other front wheel spinning in the opposite direction.

[jakebe]

That all checks out. The driveshaft doesn't spin. The one turns one way and the other the other. Still begs the question of why I'm getting the noises and lack of power in articulation.

[jakebe]

Could this be related to the power steering? I think the pump is starting to go.