2014 F150 groan in front end
#12
For what it's worth, I don't know if it might apply but... in my old 2004 it turned out I had a leak in the gasket of my front differential. When she went dry....whoa boy did I ever hear some groaning when it was in 4x4. That doesn't sound like the case with you, but when you said groan, it's the first thing that came to mind.