Clocking Speedometer

There is a cast pointer on the trans that you line up to tooth range, you can also stick it in there and rotate it as it is eccentric inside, sort of off center and youll be able to feel it hit the worm gear, then back it off so the numbers match the pointer. If your speedo is not working, you can chuck the end of the yellow gear in a hand drill amd rotate it to see if it registers on the speedo.