there is only one position the data wheel will fit perfectly in... it has a slight indentation on one part that only makes it fit in a certain position... this is why when you remove the data wheel, you need to align it a certain way and remember how you left it [i usually leave mine pointing at 12 o'clock so that i can put the knob back on in that same position later...
for now it sounds like you're going to have to try every position of the knob until it finally fits correctly and goes further down.