The rear window keeps coming off the mechanism that guides it up and down. I pulled the door apart and found the little wheel that slides in the track likes to jump out now and then. It seems like the wheel shouldn't be this close to the end of the track. Is there something out of adjustment here or am I just destined to pull the door apart every couple of months? This shot is right where the wheel stops going to the right and then goes left to roll the window up. Thanks.