I have a 2017 2.7 4x4 Lariat. No extra towing package but I have the dealer installed OEM electronic brake controller, and 3.55 gears. Truck is rated to tow 7500 lbs. At what point does one need an add on trans oil cooler? I am planning to tow a 23' lightweight trailer ~4000 lbs with water in tanks. For example would I expect trans oil heating problems towing this up a grade of 8% for 6 miles? That is the grade on I-24 going West at Monteagle, TN. That is a particularly steep grade.
How about towing without steep grades? At what point does one need the add on oil cooler?

 

Your Eco will run at 200 degrees as is. Towing of any kind adds some heat. A travel trailer of any weight will add wind resistance which is the real enemy. An added trans cooler may not work like the Ford on which is computor controlled if you have the dealer do it it may. I do not know how sensitive the Ford computer controls are to trans temps but I like to keep mine at less than 200 which I could not do even with all the Max Tow options.
No matter what path you choose drive slower and manually select lower gears when climbing. This little engine is going to work which it is designed to do but don't kill it, just use it.

 

We have the 3.5L EB, and it does have the tow package. We usually just turn on tow mode, and the tranny does pretty good. It's sometimes a bit aggressive on the downshift during a downhill run, but is right on more than 95% of the time. We have the 3.31 rear end.

 

I wouldn't add another cooler to a new truck unless you are towing over it's capacity and along with jimmy-six I'm not sure how these new trucks would react to an additional cooler since it always runs 200 even when empty, Ford likes their transmissions to run warm.

And if you were towing that much weight your trans temp would be the least of your worries.

Just try it out and if you have problems then address them with Ford. My "pull over and let it cool off" trans temp is 240. I got 2 different Ford trucks up that high and put many more miles on them with no issues and no oburnt trans fluid smell.

With my 2015 Expedition EL 4x4 3.5 ecoboost with max tow package I've towed 8300 pounds and the trans ran between 205-212. Empty cruising 55mph it runs 199-203 so I think it has plenty of cooing capability.

 

Gluguy.... I'm sorry but with a 3.31 gear I would really watch my towing. I had 3.73 with the 3.5 and mine worked to tow 8000. Tow selection was good in most instances but climbing I was in manual and in 3rd most of the time. Same coming down. Looking back 4.11 would have been best. With the new 10 speed I'm hoping it will be better.

 

No need to be sorry. I have noticed that the transmission will be one gear lower than you might expect. However, even with the lowly 6-speed, there seems to be plenty to choose from. It's not like the old Powerglide days.

 

Appreciate the replies.
I am going to plan for a different first towing experience that doesn't involve a steep tow, and see how it my truck 7500 lbs rated F150 does pulling a ~4K lbs travel trailer in general. This is all new to me.

 

Once up to 55mph weight become almost irrelevant, wind resistance is your enemy. You shouldn't have any issues, but just keep an eye on it the first trip and don't lug the motor. Use the gear selector to keep the engine in the peak torque range if it doesn't do so itself. Slow gradual take offs will go a long ways to keep trans temps down in stop and go traffic and remember to give yourself a good bit more stopping distance then normal.

 

I wouldn't worry about it. Transmission cooling has improved by leaps and bounds in the last twenty years.

The last time I heard of someone overheating a transmission was a few years ago...he toasted the transmission trying to rock the truck out of being stuck in snow. He was in 4WD, and there was minimal airflow through the cooler because the truck wasn't moving. I've heard of people overheating the engine towing heavy up a mountain, but never the transmission.

Put the truck in tow/haul and pull your camper. No need to fuss with manual gear selection unless you want to; you won't hurt it.

 

Nope, these transmissions use a simple mechanical thermostat just like engine cooling systems have been using for decades. The computer has no input here.