It's not coming from the transfer case, it is coming from the transmission. It is the sound of your parking pawl being destroyed by rocking the truck in Park.
Yes, it is ridiculously loud. It is an electronically generated sound and not an actual relay click , like the flashers from the days of yore. Someone on this forum removed their instrument cluster and put foam over the speaker. But that also affects the sound of other chimes and...
It is just taped onto the tailgate. Mine flew off over a year ago somewhere between New Jersey and Virginia. Shortly after that incident, I lost both of my wiper arms. I've never owned a vehicle that had so many parts just fall off.
No dipstick under the hood and “sealed for life” tells me that Ford likes to sell replacement parts and new trucks. There is no such thing as "maintenance-free" machinery.
In that case this shows that it is possible to have a 4 Auto transfer case without the 4A default in Sport mode. Now I just need to figure out how to make that happen for my Platinum.
My neighbor sprays down his calipers every couple of months with white lithium grease in a spray can. He doesn't even take the wheels off, just sprays through the wheel spokes.