Thanks in advance for reading.
2003 V6. I've noticed the past few days a "clicking" sound coming from the front right. Almost like a nail in the tire. Can hear it about 20 mph or so up.

Took the tire off, no nail, rocks etc in it. Noticed that the front right side would not fully rotate, as the diff stopped it. Would go 3-4 inches to the right, stop...3-4 inches to the left, stop.

I thought maybe because the driver side tire was on the ground....
so I jacked both tires off the ground...Right front still will not fully rotate...but driver side will? I put the truck in neutral, and same results.

No CEL's, when I engage 4wd, the lights flash.....then green 4wd light stays on..I hit the VSC button, it locks and lights indicate that, turn off, no issues...

I did have an issue over the winter where when i was driving in 4HI, I would get kicked CEL codes. Thought they were engine related, and read online the codes were fuel cap related, so I bought a dealer fuel cap and replaced it. No CEL's in awhile, however, I haven't driven it in 4wd in awhile either. Not sure if they are related, or if it is coincidence.

I was under the impression that in 2hi, the tires and drive axles would spin freely?
So I guess my first question is, should the drive axles spin freely when in 2hi?

Based on your second paragraph it sounds like a stuck caliper.

Didn't think of that, my pads look evenly worn. I will scarf down dinner and hit the garage, take the caliper off and see what I have, thanks friend.

I'd suspect the CV shaft. Clicking and binding are common when they fail.

2 inner pistons of caliper frozen. I will buy another caliper and see how it fairs.
Also still could be an issue with the cv joints. I replaced the drive axles 50k or so ago, and not with superior parts. A few times I've heard a clunk, and actually felt something when I heard it. So they could be shot as well. Truck has 252k on it, and hasn't let me down 1 bit, so I'll spend a little on it to keep her honest. Thanks guys, will update after install the caliper.

Also, you mentioned binding, is that what is going on, and I assume thats not normal?

Could be. Start with the calipers since you already know they are bad. That may very well fix your problem. No need to just assume the CVs are shot unless the boots are torn or something.