I pulled my typical sized load at freeway speeds and my trans was the same temp as it is empty.. haha.

I had my Bronco on my 18' car trailer, can't even tell it's there.

 

I have read many of your posts in the past Mark and have learned much from them. I appreciate your sharing your knowledge and taking the time to post.
I do understand you were out of Ford by the time the 6R140 reached production.

Transmission temperatures have been a subject of discussion in my group of late.
Perhaps yourself or another on the site can help me understand variations in the different production years of the 6R140.

Let's compare 2 of the trucks in my ride group. Mine is a 2017 F350 6.7 CCSB KR with 3.55's.
Truck #2 is a 2015 F250 (but with HD trailer package) 6.7 CCSB with 3.55's. Both trucks of course have the 6R140.

My transmission performs as I would expect. Towing a 12K 5th wheel on grades I see the low 230's regularly. It seems to stay there regardless of the conditions I tow under so I assume the trany thermostat must open around that temp.

Truck #2 towing significantly more weight under more harsh conditions will barely get over 200 degrees.
I would like to better understand what makes these two 6R140's so different in operating temperatures.

Some other information I have become aware of but would like further information or verification on...

1. I read somewhere (can't find it again) that the digital readout for the transmission will turn yellow then red as temperature gets higher. Is this true and at what temps does this occur?

2. What temp does the truck enter limp mode and is this based on more than trany temp (maybe engine temp also?).

 

I have no answers for your questions. All I could do is guess because I left Ford before the 6R140 was developed. I've never seen a 6R140, nor have I even driven one.

 

Well, I didn't follow through on my threat ... I haven't completely ignored the temp.

Towing 7,000 lbs up the Ike Gauntlet, 65-75 F ambient, at or slightly above the speed limit of 55-70 mph, and in Tow/Haul mode with 6th gear locked out: held pretty constant between 200 - 220 F. Got hotter when I'd downshift to pass or to accelerate after traffic slowed me down. On the most aggressive climbs (heading east from Silverthorne), my transmission would drop to 4th gear for a bit and temps climbed as high as 232 F.

Engine temps would climb, too. But, when my engine gets into the low 220s, the fan kicks on. Holy crap does that thing work! Within a couple of minutes, even as my engine is working hard up the 7% grade, my engine is down to 182-185 F. The transmission benefits from this fan, too, but not nearly as quickly.

Towing the same load, 7,000 lbs, gradual trip from 5,000' to 7,300' on I-25, heavy traffic with lots of slow-downs, 85 F ambient, Tow/Haul mode with no gears locked out: held pretty constant between 200 - 220 F. I saw a couple of times it had crept up to 233 F after working through the gears in slow-and-go traffic.

Conclusion: when under load, the transmission will live in the 210 +/-5 range most of the time. When under load and working through gears, the transmission will creep into the low/mid-230s, but will generally be cooled with the engine fan.

 

This comes up quite a bit, and a lot of people do not understand what the Ford engineers were trying to accomplish with the desired temperatures they set. A lot of people just think higher temps = bad. I even see guys installing auxiliary coolers....don't do it, its a waste of money and its even worse for your motor. The ECU is set from the factory to try and keep the coolant at 221F. They do this to try and keep water out of the fluids, keep the oil viscous for lower resistance and better MPG...

The tranny temp is ok up to 250F, the fan doesnt come on until it hits 246F. Ford designed it this way. Leave it be and let the truck work in the way it was engineered.

This guy actually lays it out pretty well:

 

The new trucks have more technology built into them than we realize. Those of us that are used to monitoring everything because we used to own a 6.0 need to break ourselves of the need (compulsion) to monitor everything. Kinda like quitting smoking...eventually you'll not need to do it anymore but it's a hard habit to break.
I now just drive the truck. If something is out of temp the truck has enough sensors and computers to let me know. Now, I just drive. No more constantly eyeing the Torque pro. It's really a great feeling to just drive. 😀

 

Excellent video T. I have no issue or concern with the higher temps the tranny runs at.

The question remains however.
Is the 2015 (or before) 6R140 the same as the current 2017+ 6R140 and if not what has changed?

Is it all programming and fluid changes? Is the secondary cooling system different? Is the tranny thermostat circuit different?

The information in the vid for both the engine and tranny fan programing is really informative. Thanks for posting it.

 

Good point.

For that very reason when making the many changes I have using Forscan I decided against putting up the digital readouts for engine and tranny fluid temps.

It's enough for me to see them when they come up in stock configuration. I must admit I am amazed at how quickly the fan brings down the engine coolant temp.

 

My 19' runs the same exact temp empty as it does pulling my rock crawler with a bed full of gear at the same speeds. It's kinda amazing-

 

Funny as I asked this same question after I purchased my '17 F-250 with the G transmission. I saw trans temps in the 199-203 range while not towing and thought something must be amiss. Found out about the thermostatic control and thought ok. First time towing my 9K Eagle in 90* temps I never saw temps above 207*. Was very pleased.

 

This couldn’t have been said better, the 6.0 owners used to monitoring everything I know the feeling I’m the same way with my 2019 now... well said

 

First time I drove the truck empty I was surprised too. We used to think 220F was ready to overheat and mine runs at 204F going to pick up lunch! Times change.

 

Yep and I watched my EOT spike higher/faster then my ECT on torque pro on my 6.0s last tow into Asheville. Watching it happen in real time on my screen didn't change a damn thing. It got towed into the dealer as a trade for the 6.7L.

These new trucks are not going to let you hurt them. Drive it. I also enjoy the fan kicking on high at 246F E0T. Sure does cool down quick. I keep it on the oil temp screen out of habit....but just plant the throttle and go.

 

Pulling my 5th wheel, I have never been able to hit 210 f. I like my transmission more than the newer version.

 

This would be more informative if you gave us a clue as to what you’re driving.