I can't speak directly to a 36 because I have not owned one but generally there are a couple of bushings for the kicker "axle" shaft and a seal between them. Is there an "upgraded" seal? I don't know that either but there is always a "new" seal which normally does the trick for me. There are also "new" bushings.
As for the other problem, since you don't know where the leak is, it is going to be a little tough for someone to tell you how and what to fix. Why don't you remove the trans from the bike, wash it off in solvent, fill it with oil to the proper level (just below the fill hole), sit it level on some newspaper on a bench, go away for a few days, come back, and then try to see what if anything happened in the meantime.
It can leak from the main drive gear bushing, the main shaft bushing, a cracked case or kicker cover, an over-filled trans, any one or more of the 4 mounting studs, the bolt under the right side bottom area near the kicker, a bad kicker cover gasket, a bad lid gasket, or a worn out filler hole/plug. Maybe you have a pin hole leak in your oil tank with just enough leakage that you cannot readily spot from the oil tank, which makes you think it must be a trans leak. You get the point.
New Knuckleheads? Thank, you, Jesus!!