Hi, I just finished the my first ever OldFrogShot's Screw Mod (very famous method of altering the Frog geared differential to stop it separating so that the gearbox side plates don't bend outwards and the diff. never again grinds it's gears to pieces as a result of the side thrust from the diff's bevel gears when using powerful motors) and it was an interesting job. Link to OldFrogShot's screw mod ;- http://tamiyaclub.com/showroom_model.asp?c...74&sid=3142 I bought 2.5mm Dr