20. The two shifter forks drop into their slots and cut into the gears, then you can install the slider shafts into the case and through the ends of the shifter forks. The forks connect to the slider shafts with the roll pins included in the rebuild kit. It's easy to get the two shafts confused, just remember that the reverse shaft (the lower one) has two notches while the primary shaft only one. Also, use plenty of high-pressure lube to protect the shafts until the ATF has a chance to work its way in there.