Shadow Potatoe

I have a new to me GMC canyon all terrain edition, tons of towing power and a fairly decent payload capacity. My only concern is how do I haul heavy loads without hurting the transmission. I can haul up steep hills in 4wd low pretty easy and the transmission hardly gets warm. Go nice and slow and everything thing seems a ok but is it? Am I causing excessive wear? Or is it designed for hauling. I haul lots of things with tractors but am new to the world of pickups. What do you guys know? Also idk of anyone actually uses this fourm