Has anyone installed a transmission temperature gauge or used a OBD computer to measure the transmission temperature? One of my gripes of the Expedition versus the Suburban is that the Suburban message display will show the transmission temperaure, but the Expedition does not. I have the heavy duty tow package, but I'd really like to know that the transmission isn't running too hot with my 30' #5,500 (loaded) travel trailer running in the AZ heat loaded with my family of 7. I don't understand why Ford didn't program this into the message display since the data is already in the computer already. Personally I think this is a purposely witheld feature that will be added in a later years and promoted after all the new model buzz has faded.
I wondered this too as I have the tow package also. It would be nice to know as towing on long steep grades, going through heavy snow can really increase transmission fluid temperatures.
I never lost a transmission just to steep grades alone on dry pavement, but lost a C4 and a C6 going up grade through several miles of deep snow. I think the, slower engine speed, slow car speed in low gear = less transmission cooling even with a add on heavy duty fluid cooler.
Had a Allan Root built 460 on one side of the B and M C6 and heavy snow with tire chains on the other side of the B and M C6. The transmission rubber cooler lines got so hot they just snapped into when bent.
When I pulled the C6 apart, the shafts got so hot they turned blue and the clutch packs would NOT come apart even when I tried using a hammer!
The transmission was not rebuildable. Just scrap metal.
After this, I always put a temperature gage in the transmission pan, then if I seen it going a little over temp while under a load, would just stop in park and run the engine at a fast idle until it cooled down and then went on.
Never had another problem after that. It was money well spent.