How is the ring and pinion gear mesh adjusted on these things? I know how to do it on a 1:1 car by adjusting the pinion depth and ring gear from side to side until the backlash and pattern are correct, but I know we're not concerned with the pattern on these and only need to get the mesh correct. With these, there is no rear cover, so you can't install the pinion and feel the ring gear, so what do you do? Do you just hold the rear yoke and feel how much play there is by rotating a wheel back and forth? If there is too much play, do you shim the pinion deeper or do you shim the ring gear? Where do you get the shims?