TODAY is a Great Day to visit our Store and order the parts you need for your truck!
My $0.02, Take your shifter off, disassemble and thoroughly clean it. When reassembling, thoroughly grease the parts.
Remove the shifter knob and boot. Spread a plastic under the truck. Using about half a can of Silikroil, or PB Blaster, or WD-40, soak down the whole shifter mech, shooting down through the shifter hole in the floor, while working the shifter lever back and forth. Let sit for a couple hours; best is overnight. The next day, hose it down with the other half, while working the shift lever back and forth. It should get very smooth and easy to move. Now pour a little engine oil down into it and work it back and forth some more. Replace shifter boot and knob. Remove plastic and discard.