Rear Windows

I have a 4 door 96 Tahoe and am wondering if the back windows are supposed to roll down all the way or just part way down. My windows only go down about 4 inches.

Same on my 99 Tahoe. I remember reading a post a long time ago somehwere about this. Thats as far down as they go.

It won't go down any more because the door is part of the wheelwell...