The planetary in a automatic is a constant mesh and constantly spinning.
Bearings I can see since there is no side load. But between how hot the automatic clutch packs get, the bands, the torque converter, and the weight it can move. I'm still seeing it hard to believe my quad is breaking it down in a few hours.
Has anyone done any sort of testing? Be it temp, viscosity, actual lab test? I'll take anything.
I'm just thinking out loud, so please if anyone has actual facts please shoot me down. If not I would like to keep the ideas going