All of the felt/channel is worn out in the tailgate in mine. It squeaks and rattles as I roll it up and down. Could use another lube job. It was all apart in the back of the truck when I got it. Since you can't drive these trucks with the back window down without a truck full of exhaust fumes anyway, I only care about the channel holding the glass in the top when its up. This is a flimsy mechanism, that was designed for 2 things, to bring the glass up and down during warranty and to make money on parts for GM afterward. If your window sticks, stop and figure out why. If you continue to crank when there is a bind you will regret it. Mine has bound up many times and its always something keeping the gate from closing completely on one side. The latch to open the gate can become bound up by shutting the gate hard with something in the way. Once had $300 worth of groceries from costco in the back and something was hitting the gate under it all. Pouring rain in the dark, jammed tight, window wouldn't go all the way up and the gate wouldn't open. The tire iron was jammed under the tire and against the gate. Still have the rotting groceries back there from last year. Seriously, it was a real pain removing everything thru the front and still couldn't get it out and the gate open without removing the spare tire.