Jethro, I'm from Toledo IL. The screw that I'm referring to is not the high-low limit screws. It's the one on the back of the derailer that pushes against the hanger. It moves the linear movement of DR up or down in relationship to the cassette rings(distance of jockey wheels to rings on the cassette). I have been unsuccessful in getting it to work as it did prior to this week, maybe it's just time for a new one.