So... I've got a few questions / concerns regarding transmission temps on our 2012 F250 crew cab short bed XL FX4 6.2L gas with 3.73 rear end. We bought it used with 102k on it in late spring as a tow /utility vehicle - primarily for towing our travel trailer (2018 Keystone Cougar 28RLSWE ) plus the occasional trip to HD/Lowe's.

We've put about 5k on it so far, including one two week 3500 mile marathon road trip towing the TT through WA ID MT ND SD NE & WY. The six speed transmission plus tow haul mode worked *great*.

That said, I noticed that the transmission temp gauge on the dash never moved, even when climbing mountain passes in ID, MT & WY. Even more interesting is that the transmission temp does not show up anywhere in the list of values available from the ECU when I have an ODBII BT adapter plugged in and monitoring via an app (Torque) on a dash mounted tablet.

Normally I wouldn't sweat it too much but we've noticed on more than one occasion that the rear floorboard over the transmission is... well, maybe not *hot* but bordering on 'uncomfortably warm". As in "melt all the ice in the cooler while the AC is cranked" kind of warm. Yet the dash gauge never moves, and it's oddly missing from ODBII.

If it's nothing to worry about, great. But if something isn't right I'd prefer to get it addressed before things go pear-shaped on the road far from home

 

The gauge won't move at all over a very large range of temperatures. That's by design. I don't know anything about the values available to view on that vehicle.

 

in the normal position...I see 200 just running down the road, no towing.

When towing and working it hard the guage does not move but the temps rise around 210-215. That is about it.