Front axle shift fork
Remove the black plastic cover,,and have a look,,,could be froze up,,with little use,,spray with fav pen oil and work it a bit.
You would feel pretty smart,,if you fixed it that easy,,,LOL,,,
On my son's 01' F-150,,acctuator was kinda stiff,,lubed it up,,atleast we new it worked,,,on his truck, (a manual shift 4x4 lever) his 4x4 did not work,,all it was is, when placed in 4x4, the transfer case was engaged but not the front end,,,it was the "oil switch" the electric switch in the transfer case that makes the "4x4" light in the dash come on,,,with out the light being triggered,,,the GEM module was'nt pulling the front diff acctuator in,,working great now for almost a yr already,,,,and this truck had 187 k miles on it when we got it !! He's getting closer to 200 k on this truck every day,,, it is a,
2001 f-150, XLT, S-cab,4.6, 5-sp, 4x4. good Luck !
Take it to a different dealer. or if your mechanically inclined, do it yourself. It's been 10 years since I did it but basically remove shift motor, split tube, remove broken fork and replace ---- if I remember right that is.




