2025 Slushbox Operation Temperature
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
yeah, that’s the bottom line. I do stand corrected. I thought the bigger one was code developed like the smaller units. If you want to reduce your trans temp lock out ninth and 10th at lower speeds.
More Turbo
Joined: Nov 2011
Posts: 740
Likes: 92
Logistics Pro
Joined: May 2022
Posts: 4,285
Likes: 2,416
From: Everywhere and nowhere
ULV is fine running 215F ALL the time without causing any damage.
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
because heat kills fluid. That’s true today like it was three generations ago. And I know about new synthetic and stuff that have higher heat capability. Sounds like the Ford runs hotter for emissions reasons. That’s not a good reason to run it hotter.
Cargo Master
Joined: Jan 2017
Posts: 2,250
Likes: 561
makes a guy wonder what they were thinking. 1mpg better fuel mileage ? 2hp more ?
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
How it works. Needless complexity. The 10R140 uses a coolant control valve in its transmission fluid cooling system, which is attached to the coolant return hose. This valve, controlled by the PCM (Powertrain Control Module), restricts coolant flow through the warmer when the fluid is cold to help it warm up faster. Once the fluid reaches a predetermined temperature—around 220°F according to user reports—the PCM signals the valve to open, allowing coolant to flow and cool the fluid, maintaining an operating range of about 208-221°F. This design prioritizes fuel economy by allowing the transmission to run hotter, as higher temperatures reduce fluid viscosity and parasitic drag, though it has raised concerns among some owners about long-term durability.
More Turbo
Joined: Nov 2011
Posts: 740
Likes: 92
How it works. Needless complexity. The 10R140 uses a coolant control valve in its transmission fluid cooling system, which is attached to the coolant return hose. This valve, controlled by the PCM (Powertrain Control Module), restricts coolant flow through the warmer when the fluid is cold to help it warm up faster. Once the fluid reaches a predetermined temperature—around 220°F according to user reports—the PCM signals the valve to open, allowing coolant to flow and cool the fluid, maintaining an operating range of about 208-221°F. This design prioritizes fuel economy by allowing the transmission to run hotter, as higher temperatures reduce fluid viscosity and parasitic drag, though it has raised concerns among some owners about long-term durability.
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
if you ever really wanna learn about fluids and viscosity, look up the motor oil geek on YouTube. Prepared to be amazed.
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Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
and honestly, I think the part you’re missing is all they need to get you is out of the warranty period.
Cargo Master
Joined: Jan 2017
Posts: 2,250
Likes: 561
heres a snipit from a article on the ford 10spd. full article below. also explains why it shifts so clunky
Additionally, the OEM stator, the component responsible for controlling stall speed, is absurdly high stall. This is because stators have a notable impact on idling emissions, something the EPA is deeply concerned about. To the benefit of our consumer, we don't give a **** about the EPA. Our priority is on reliability, functionality and driving dynamics; things relevant to you as the owner of the vehicle.
Lastly, and as a collateral effect of the stator, the OEM converter escalates average operating temperature (AOT) by a considerable margin because the large allowable difference in speed between the motor side and the input shaft side of the converter is so immense. This generates huge amounts of thermokinetic energy, a chemical reaction producing heat. Heat is a silent killer in the transmission world, and detracts from the longevity of any transmission
https://nextgendiesel.com/blogs/tran...lems-solutions
Additionally, the OEM stator, the component responsible for controlling stall speed, is absurdly high stall. This is because stators have a notable impact on idling emissions, something the EPA is deeply concerned about. To the benefit of our consumer, we don't give a **** about the EPA. Our priority is on reliability, functionality and driving dynamics; things relevant to you as the owner of the vehicle.
Lastly, and as a collateral effect of the stator, the OEM converter escalates average operating temperature (AOT) by a considerable margin because the large allowable difference in speed between the motor side and the input shaft side of the converter is so immense. This generates huge amounts of thermokinetic energy, a chemical reaction producing heat. Heat is a silent killer in the transmission world, and detracts from the longevity of any transmission
https://nextgendiesel.com/blogs/tran...lems-solutions
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
heres a snipit from a article on the ford 10spd. full article below. also explains why it shifts so clunky
Additionally, the OEM stator, the component responsible for controlling stall speed, is absurdly high stall. This is because stators have a notable impact on idling emissions, something the EPA is deeply concerned about. To the benefit of our consumer, we don't give a **** about the EPA. Our priority is on reliability, functionality and driving dynamics; things relevant to you as the owner of the vehicle.
Lastly, and as a collateral effect of the stator, the OEM converter escalates average operating temperature (AOT) by a considerable margin because the large allowable difference in speed between the motor side and the input shaft side of the converter is so immense. This generates huge amounts of thermokinetic energy, a chemical reaction producing heat. Heat is a silent killer in the transmission world, and detracts from the longevity of any transmission
https://nextgendiesel.com/blogs/tran...lems-solutions
Additionally, the OEM stator, the component responsible for controlling stall speed, is absurdly high stall. This is because stators have a notable impact on idling emissions, something the EPA is deeply concerned about. To the benefit of our consumer, we don't give a **** about the EPA. Our priority is on reliability, functionality and driving dynamics; things relevant to you as the owner of the vehicle.
Lastly, and as a collateral effect of the stator, the OEM converter escalates average operating temperature (AOT) by a considerable margin because the large allowable difference in speed between the motor side and the input shaft side of the converter is so immense. This generates huge amounts of thermokinetic energy, a chemical reaction producing heat. Heat is a silent killer in the transmission world, and detracts from the longevity of any transmission
https://nextgendiesel.com/blogs/tran...lems-solutions
More Turbo
Joined: Nov 2011
Posts: 740
Likes: 92
I'm not saying the 10R140 is a fantastic transmission, or a garbage one. My contention is that arguing trans temp guidelines that are not specific to the transmission and fluid is an act in frivolity. It is 100% irrelevant what any other transmission should/would/could run. The 10R140 with Mercon ULV is designed by Ford to run 200-215F unladen and is within Ford spec for temperatures much higher. This is really the only "scientific" information we have. Stating that you need to run your Ford 10R140 at -75F for optimal service life is anecdotal. Zero empirical evidence as been presented to the contrary.
