I should also mention that the drive gear, which is pressed onto the u-joint yoke, needs to match the driven gear, shown here above. Sets of gears with different tooth counts allows the same transmission to function correctly with different sized wheels (for example 16' vs 20" wheels). Note that the two gears pictured above do not have the same tooth spacing/count. So you can't just slide whatever driven gear you have into your tranny and expect it to work.
Kent
