Chelsbug01

4x4 front end locked up The front end on my 2000 1500 Silverado locked up while driving. It will not move. What can I do to fix it and what caused this?? I wasn’t driving when it happened so I’m not sure about much that happened. I let my dad borrow it and he’s a mechanic but he’s getting up in age (not really but really) and he’s not able to fix it or look at it. I don’t have front breaks, but that’s nothing new.