I tried what you said but i became worst (maybe because of the type of fuel tubing) so what I did is clean all af the grease and I took a very heavy sand paper and sanded the metal piece in a straight fashion and with a light sander I barely sanded the plastic teeth and now its silky smooth, and it wont move even when you slam the rudder stick but when you put throttle input it wont stick and its just smooth. I highly recommend this simple mod if you want you dx7 to feel like a much more expensive radio.