Passenger side window will come down, but will not go up. I can hear the motor trying, but whatever is connected to the motor just won't force it up. It has gotten to the point where when you hit "up", the window comes down, are the gears slipping?

 

There are three ***** in the gear mechanism of the motor. They are called the clutch. They are made of plastic and have now disintergrated. You can either replace the window motor, a rebuilt one costs about 60 bucks, or put a kit in yours. Check with your local parts house.