You should be able to tighten the screw securing the gear to the shaft on the Alton, then check the gear back and fourth to see if any backlash exists........this is what you want.......even though the gear is black plastic it still needs to have some clearance.........The last one I mentioned earlier, the screw holding the gear to the shaft had come loose and fallen to the bottom of the timing chest, luckily it did no harm, but the bearings in the Alton were shot.