two things
1 I say the front axles are turning all the time even in 2wd..the lockup is near the differential.
2 you said there was a "neutral" mode for towing? not on the switch. nice presentation though.

 

Ya, there's no neutral on the switch, I think it is described in the owners manual how to get the TC in neutral. Probably should read it again, I don't remember how to do it.
They will turn, especially if you have 4A due to the clutch in the TC. Sorta "leaks" power forward.

 

Since it turned cold here in my neck of the woods I starting having the same issue as described by original poster. Comes and goes mostly off throttle. when coasting of the gas can really notice it. Seems less in 4h , does not change with 4A. I had my front differential rebuilt last year under warranty.

 

If it is IWE related and you say it doesn't change at all in 2H, 4H or 4A then I'd suspect one or both IWEs not fully engaging. With the truck running and in 2H, you should be able to fairly easily turn the half shafts by hand. They should turn smoothly. I'd have the wheels straight when doing this just so that everything is straight.

I'd also suspect a wheel bearing.

 

According to the tech's report on the paperwork the, parts within the hub were damaged. For the life of me I can't understand why in the world the hub would be replaced, but only one bearing. The clunking in 4wd is gone but the droan is still there in 2wd. However, if I cut the wheel to the left, the noise goes away. My guess is the bearing that wasn't replaced is the culprit. Going in again tomorrow to have a tech ride along and see what he thinks.

 

Grinding from the IWE(s) have been known to get into the wheel bearing and ruin them. That is why it is essential to stop the grinding ASAP and try to minimize it while trying to diagnose where exactly the issue is.

 

Kinda sounds like a bearing to me.

 

As the actuators are aluminum they likely got shavings into the bearing which is not replaceable, you have to do the whole hub.

 

So you are saying the bearings are not serviceable? The parts list shows one bearing. What would it have been for?

 

The bearings and the IWEs can be replaced separately.

Bearings are not pressed out and then back in. You replace the bearing and the bracket it is in as a whole. Remove 4 bolts and the bearing is off. Reverse to put the new one on. Part costs more but, you pay less in labor. With as expensive as the bearing is, it’s almost a wash.