pull those clutches out that are around that drum. then take your hand and grab that roller clutch on that drum that you have a airrow pointed at, spin it and wiggle it, until it drops back down, what u are doing is engaging all the clutches in that drum, on the splines of the second drum. You will know if everything is in place if you put the front pump back in and as you tighten the front pump bolts turn the input shaft, if it ever quits turning stop, something is not in all the way, if it goes good, tighten the bolts down and make sure you have some endplay in the input shaft.