I have the exact same issue going on. When steering wheel is turned full left and rolling slowly will get a LOUD POP of metal on metal. Truck has new tie rods, control arms, struts, and ball joints on it last summer.
Its been too cold to try and get a video or get my wife out there to do it while I look under the truck...and she'll probably just run me over anyways!!!
I'm going to try and get it on a lift and see if I can recreate in the shop. Its driving me nuts though and I cant see any visual areas of metal on metal wear.
The POP is loud enough that people on the street and in parking lots have turned and looked at me when it happens......its LOUD.