I have a 1997 Chevrolet K1500 pickup. The handle to open the tailgate doesn't retract the pins enough to release it. So I can't open my tailgate. I removed the three screws from the inside of the tailgate and removed the insert. I sprayed all the moving parts with some WD40 and tried to work it in a bit but the pins just won't retract far enough when I pull the handle.
The part your referring to has a short linkage that rotates the " crank" mechanism. The short linkage is hooked directly to the tailgate handle. On either side of the " crank" should be long actuating rods that go to the end of your tailgate on each side. The wedges are what seize up, and should be lubricated and worked free. A can of PB blaster should do the trick. Hope this helps.