Every time the engine runs hotter than normal the tranny takes a hit too.
Heat is the number one killer of trannys.
You might want to install an aftermarket tranny cooler to the front of the rad.
I had one added to the rad on a 2000 Silo I used for towing a pop up camper.
You can look around the web or local auto shops for sizes and prices. Get the largest one possible.