Ya I give up on this forum honestly.

Have fun.

 

I'm dealing with the exact concerns you all have. I'm working on a 2015 F-150 3.5L for a customer. His has same noise you describe. His front drivshaft turns all the time. I removed front driveshaft and all noises are immediately gone. IWE's test fine, completely lock and disengage as designed. I have another customer with 2015 F-150 5.0L . His truck doesn't make any noises. Only difference is his front driveshaft does not spin any when driving truck in the 2wd position!

there's a issue in TC not letting it disengage correctly an I prematurely wearing out the TC. His noise started out very faint 3 years ago. Now it sounds horrible..

 

Couple thinks to think about. I’ve been through two sets of IWE’s before I got rid of them all together. The second round still function but made a terrible crunching sound on occasion that got worse as time went on but when I pulled them they still tested fine. Second the pcm runs the TC at start up for a few miles to warm the fluid so when you compare to another vehicle are they both cold/ both hot, same conditions? Lastly I’m running over 700hp at the crank and have my TC in A4WD 24/7. I never run 2wd. Even if his is running engaged all the time it should not cause the TC to wear out. That doesn’t mean there’s not a problem with it just some thinks to think about if you haven’t already.

 

check for pinion bearing play in the front diff with the driveshaft removed. I had to have my diff rebuilt twice now on my 16. Factory built failed and the dealer rebuilt it, which failed again after only 3k miles.

when i removed the front driveshaft, the noise immediately stopped and i then discovered about .009" of play on the pinion. my noise was a faint "whine", didnt matter if i was in 2wd, 4wd or 4A. it was easier to hear in 2wd, since the TC on these trucks are noisy as it is.

 

4A equipped trucks, the front driveshaft turns in 2H due to the nature of the TC. It would help a lot to help others, if an accurate description of the truck in question was provided.
Meanwhile, take a watch of this video, yes, your nonRaptor with 4A works like this. Scroll down to the video.
Ford F-150 Raptor 4WD Explained - Raptor Has 4WD and AWD