So I had the issue of no 4wd. I checked plugs, hubs, shafts, switches and whatever I could think of.
I could see the front driveshaft turning with the truck in gear and rear tires turning. Hubs locked couldn't turn axles. All seemed normal but still no 4wd/
In a brainstorm moment I decided to put the stock hubs on to see if that made any difference. Low and behold it did. While taking the drivers hub off something didn't look the same as the other. It seems that there were a couple pieces left behind.