2023 F350 6.7 HO Towing 10k lb Review

^You mean if the thermostat is closed, it bypasses the cooler, resulting in very little cooling? That is correct.
So yes it has everything to do with cooling. Closed/bypass = no cooling. Open to the trans cooler = normal cooling.

Fwiw the OE part does a GREAT job at warming the transmission quickly.
Not long after the engine is up to full operating temp from a cold start, the trans fluid is holding right at 170 ish.
With no bypass and full cooling flow all the time, you can drive an hour and the trans hasn’t even come close to 170. Just drove to work in the Ram today. An hour later, trans was at 135deg.

Grit dog wrote:
At cummins2014, I hadn’t either, but I’m not a gauge watcher. I’d rather be jammin tunes, on the phone and/or sippin a couple road sodas on my long time coming well earned infrequent vacations.
But that thermostat/cooler bypass thingy as I understand it either works great or it doesn’t work at all. If I towed more or worked my personal truck harder I woulda replaced it 3 years ago when I bought the truck.
(I also didn’t realize how stupid simple it was to remove and replace. I did it along with a trans service but by itself, it’s a 0 beer job (can’t drink laying on your back with trans juice dripping all over lol), so call it a 30 minute job including refilling a few lost units of trans blood).

What I understand about the bypass is that it does nothing for cooling , just insures the fluid is flowing .

Cummins12V98 wrote:

FishOnOne wrote:

Bionic Man wrote:
My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.

You mean this Amsoil fluid and his aftermarket finned oil pan. We know all about it. :B

Must have been very impressed to save that pic!

Or he forgot it was a simple gasket that failed, like many do at times before the REST of the unit fails!

Marty

FishOnOne wrote:

Bionic Man wrote:
My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.

You mean this Amsoil fluid and his aftermarket finned oil pan. We know all about it. :B

Must have been very impressed to save that pic!

At cummins2014, I hadn’t either, but I’m not a gauge watcher. I’d rather be jammin tunes, on the phone and/or sippin a couple road sodas on my long time coming well earned infrequent vacations.
But that thermostat/cooler bypass thingy as I understand it either works great or it doesn’t work at all. If I towed more or worked my personal truck harder I woulda replaced it 3 years ago when I bought the truck.
(I also didn’t realize how stupid simple it was to remove and replace. I did it along with a trans service but by itself, it’s a 0 beer job (can’t drink laying on your back with trans juice dripping all over lol), so call it a 30 minute job including refilling a few lost units of trans blood).

Bionic Man wrote:
My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.

I saw 203 once on my truck with the 68RFE , nothing for me to worry about .

Cummins12V98 wrote:

cummins2014 wrote:

Cummins12V98 wrote:
RAM having adjustable spots is a waste of money as I set mine once to the furthest out position and never adjusted again.

My big concern for the FORD is the HOT transmission temps. I never see over about 172 pulling in near 100 degrees on long 6% grades. Most of the time I run 165-167.

Shows how dumb it is to do a leveling kit on a tow vehicle.

No denying it it has a ton of power!

I don't doubt the Aisin will do that if you say so ,the 68RFE will not running those long grades. I will see nearly 200 with my 68RFE , solo it runs a pretty consistent 172 , towing in hot weather it's a consistent 185-190 .

My 68RFE in my HO DRW never saw 200 unless it was stop and go. For sure it did not run as cool as my AISIN does.

Maybe the Ford at those temps gets better mileage???

The nearly 200 is stop , and go city , should of said that , long grades as said will run 185-190. in 100 degrees or more . If on the flats towing my fifth wheel 15,500 GVWR , I will run pretty steady at 180 -185 in 100 degrees . I don't see much flat towing where I go , Utah , Idaho ,and Montana, pretty much always climbing a hill somewhere . Not concerned at all at the temperatures the trucks runs . I will see 215-219 on the motor climbing the grades ,not concerned with that either . The bypass on the transmission was mentioned by Grit ,I haven't had an issue with that YET .

Bionic Man wrote:
My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.

Towing what, where?

Bionic Man wrote:
My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.

You mean this Amsoil fluid and his aftermarket finned oil pan. We know all about it. :B

My 68RFE regularly saw temps above 200*. 220* was pretty common for me. Must be that Amsoil fluid that keeps yours so cool.