Setting the Pinion and Spur Gear Gap

The proper relationship of the pinion and spur gear is crucial to the performance of your truck. There needs to be a small gap between the gears. However too much will result in stripped spurs, and too little will introduce friction. After a while you get a feel for how to properly set the gap. Until you feel comfortable with that, using the "paper method" will provide you with the best results.

To do this, you take a small piece of notebook or copier paper and place it between the pinion and spur gears. Then hold the paper in place while you slide the motor forward. While holding the motor in place, tighten down the motor screws. After this procedure you can spin the gears by hand to release the paper. Once you remove the paper, you should notice a small gap between the gears as well as a little play. The picture below details where to place the paper.

Between this and the proper adjustment of the slipper clutch, you should experience very few stripped spur gears. However if this doesn't resolve frequent stripped spurs, you might need to address the transmission housing itself. For more information regarding that, see my section on the motor mount.