Right rear window sounds like its sticking

[Comptronic]

Recently, every time I roll down the right rear window in my 2004 Explorer, it sounds like its stuck in the upper part of the jam for a quick second, then continues to go down. I checked to see if there was anything making it "stick" to the jam and I can't seem to find anything.
If this information is to vague, please let me know.

 

[High_Order1]

Mine did the same thing, except that it stayed stuck for days at a time. I greased everything, checked the motor... nada

....until I replaced the car battery. Notta single problem since. Weird, I know.


Shawn