Apparently theres two different version of that tranny case. The one I have has a plastic housing and aluminum mounting plate and heatsinks. Mines old though so maybe the new ones are all aluminum now. I aint testing it. A) i dont care enough to do it and B) I'm swamped with work from my job...
The tranny case isnt even that heavy. Its all plastic except for the motor mounting plate and the heatsinks.
The heatsinks work because the metal motor is touching the metal mounting plate which is in turn touching the heatsinks. So how much it works is debatable because none of us has actually...
you're stating this as if its fact when in reality its only your opinion and is not based on any sort of measurable data nor are you even an expert in the field of metallurgy or even heat dissipation. Thermal grease isnt even necessary for heat dissipation. For example, on a computers CPU thermal...
The slipper was probably set fine for the original tires but you add all that weight of putting MT tires on something that wasn't designed to run them and yeah, thats not going to be set right now.
That was probably a combination of not gearing down after putting the MT tires on it and your slipper was probably also too loose if I had to take an educated guess. I would not do a slipper delete.