Originally Posted by Myt3rocks

I just built one with the 4 gear transmission, but it doesn't spin very freely. One of the idle gears seems to have a really tight mesh to the next gear. It's binding enough that even with no motor installed, turning one wheel causes the diff to spin the other wheel rather then the spur gear. Did I get a badly molded transmission case? Is there anything I can do to free up the gears?