some H2s have tranny cooling problems, pulling a trailer or not. Average ones do not.
I've seen my temp above 200 for a few minutes when it was working real hard a couple of times.
There is nothing wrong with the transmission in the H2. "Beefed up" is all that is done to bullet proof transmissions whose housings are the same.
Do a find on here and read about ALL OF THE TRANSMISSION FAILURES.
