[Fulltiming]

With your 8V92, I would definitely recommend installing VMSpc. It will pay for itself over and over again just in reducing the anxiety levels. I use a cheap laptop running VMSpc and love it. It will not show transmission temperature as it is not electronic on our coaches. My tranny temps are typically in the 180 range on a flat road but introduce hills or stop and go traffic and it will be up in the 210+ range with ease but that assumes that the transmission temperature gauge is more accurate than the engine coolant temperature gauge. A HT-740 tranny temp gauge that rarely goes above 120 would be suspect in my mind in anything other than pretty cold weather. You will see some degree of correlation between engine temperature and tranny temperature with the exception of the use of a jake brake as Chester mentioned where going down hill the coolant temperature will drop rapidly but the tranny temp may not.