My 2002 Tacoma 4x4, auto tranny temp got up to 215 F a few weeks ago on a long steep grade for 30 or so miles. I was driving about 70 mph, the truck was not too loaded down and I was not towing.

It was early, early morning, and the outside temps were probably 65 F or so.

The tranny temps dropped right down when I started to go down hill again.

The engine temps went up to about 200 F.

My tranny temp gauge sensor is in the tranny pan, closest to the engine where the oil is hottest in the pan.

I also have the 180 Hayden cooler. And my tranny line come out of the radiator into the Hayden and then into the tranny again.

I'm also running the Dextron III oil.

Should I be concerned? I called Amsoil before and they said their oil could run about 10 or so degrees cooler than Dextron.

Thanks
Bill