As I recall at the max interference point the inch/lb needle will increase by about 10. There will be resistance all the way leading up to that point...I'd say something in the range of 5 to 7 inch/lbs. As I said, this is a dead simple way of doing it. When the needle hits max, you know your sector and worm are where they need to be and there isn't a lot of room. You'll know it when you hit that point.