Matt Isard,
Well, Matt I do something about what you speak because I babied a window crank gear like that for years. Unfortunately the you are at a point where you may have to replace the motor probably because the gear on the part that drives the glass is worn out. It's not often the track is worn because of the grease. It's the motor. You could take the motor out and try and replace the gear on the end, unless the end of the motor shaft is worn also. What happens is the torque on the gear increases as the window gets higher until that last 2 inches. And when you are through doing all that go to the internet or O'Reilly or your favorite parts store, Dormer makes a acceptable rebuilt motor for your truck. Don't go to the wreaking yard to get one for a couple of dollars you're wasting you money.