Well make sure you keep us updated I love threads like this but hate it when you never get to find out was it was
I think this was mentioned earlier on in the thread but it sounds like a worn / loose steering swivel pin to me. Mine knocked just like this when I first got the crew cab. One of the first jobs I did way back in July. Looks clean as a whistle under there (jealous face) so should be easy to spot. Good luck with it. Stirlingmoz
Popping in and out of the dimple in the leaves? Like a disclocated shoulder. I am just guessing by the way. It might not be loose but not in far enough so is popping in and out. Loosen the but and try and tighten the grub screw more then lock it off again with the nut. Sent from my Nexus 5X using Tapatalk
Looking at the first video, is the bottom ball joint ok, could it be banging on its limit stop, would explain why the suspension doesn't drop when you jack it up.