Been a while but life happens. Running a '19 3.5 eco w/ 10 speed on 35's. Coming home recently pulling a standard v-nose cargo trailer with about 100 cases of gatorade in it. Operating temp on Livernois tuner was 220 degrees. Had the 93 towing tune running and was on about my 5th tank of 93 since getting the tuner (usually run performance 93)
Now to the issue
Truck gears seemed to slam and the power was reduced after that. I started smelling something burning so I pulled off and about 20 miles down the highway to find my undercarriage coated in trans fluid, no constant leaks once stopped. I had it towed to the dealer that replaced the trans 10k prior to this. They said the trans overheated and it began to spit fluid from the vent and go into fail save mode. The attributed this to the shutter system not working properly and wanted to get me for $2,200 to replace the shutters. When I looked in the grill, the shutters were wide open (I was told they weren't opening all the way).
If the temp is running at 220 (i've since replaced thermostat with an SPD 170 degree-now I rarely break 200 degrees) and I got no dash indicators, how can an overheating issue be told as a diagnosis? Furthermore, what the hell does the shutters have to do with a transmission? I could see if the motor overheated and I got a light. Lastly, the shutters are designed to close on the highway for fuel economy according to Ford.
No issues since, but my trust in the truck is in limbo right now.

 

What I would have problems with trust in the Dealer, not the truck. Sounds to me like they don't want to stand behind their work.
TJ

 

If the shutters close, if the engine doesn't over heat, even if the fuel mileage is better maybe ... wouldn't closed shutters still limit transmission cooling?

 

I believe the shutters are for aerodynamics, not for engine heat management (although they could assist in a quicker warmup on a cold morning, at speed).