for the oil cooling you will need to dissassemble and seal the cover plate with automotive oil resistant silicone after solvent cleaning the surfaces to be free of all oils /greases so the super runny ATF does not seep out then ensure the shaft seals are up to the job of running properly against the polished sealing surface of the shaft. some hubs either dont have tight enough seals or use unsprung dust seals not proper oil seals, i would look up the housing andshaft size required and get a good quality machinery oil seal to match, then pick a position while its apart (brake disk mount screw holes may be drilled x2 through for filling and the motor allowed to breathe out the cable. only 20 to 60 mls are needed for most hubs more does not gain any more cooling
read the not snake oil cooling thread
https://endless-sphere.com/forums/viewt ... =2&t=37972
in which Bigmoose wrote nicely summing it up
"Build the heat flux model of a conventional motor from copper windings > radiate + convect + conduct through air to the covers and the rotor. Then the covers and rotor convect and conduct to the atmosphere.
Now replace air convection (because the radiative component is nil) with immersion oil conduction in the middle step, which is the rate limiting step. See where the gain is now? Why do we immerse an egg in water to hard boil cook it? Just put the egg in the shell on top of the fry pan and compare cooking times. And compare that with a fried egg. Liquid conduction of heat rocks."