2025 Slushbox Operation Temperature
More Turbo
Joined: Oct 2023
Posts: 700
Likes: 478
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.
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
I think the bottom line is if I were given a choice to have a transmission to run at 230° or 175° I would take the ladder every day of the week. I have a 2024 F450 I couldn’t give three ****s about efficiency but what I do want is a truck that’s still around 300,000 miles from now.
More Turbo
Joined: Nov 2011
Posts: 740
Likes: 92
I think the bottom line is if I were given a choice to have a transmission to run at 230° or 175° I would take the ladder every day of the week. I have a 2024 F450 I couldn’t give three ****s about efficiency but what I do want is a truck that’s still around 300,000 miles from now.
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
I disagree. If the fluid is designed to be in its optimal efficiency at 200F than I don't want it at 175. Now if I was able to keep my 10R140 between 200F and 215F whether it was unladen or pulling 20k pounds, I would certainly be happy about that, and would happily buy and add whatever widget or doo dad helped me achieve that.
More Turbo
Joined: Nov 2011
Posts: 740
Likes: 92
I think that’s what I’m trying to get through to folks here even that fluid is gonna start burning up at 260° sustained. You don’t have any overhead and Shurwall the truck is brand new under warranty. You’re probably gonna be fine but there’s a good chance you’re not gonna be fine down the road. And as we have found, Ford is more than happy to sell you a $14,000 transmission. And part of the fix a simple that speeds under 50 in my truck with a 430 rear lockout ninth and 10th gear and the problem is literally solved. Kind of like the old E4OD days. Get that that thing out of overdrive when you’re slow towing and logging. 90% of those transmissions could’ve been saved from doing that one thing. But there were people on the forums then too saying the same BS if they didn’t want you to use overdrive, they wouldn’t have put it on the stick. Of course they had bad valve bodies and a bunch of other nonsense wrong with them, but still could’ve been saved.
More Turbo
Joined: Oct 2023
Posts: 700
Likes: 478
I think the bottom line is if I were given a choice to have a transmission to run at 230° or 175° I would take the ladder every day of the week. I have a 2024 F450 I couldn’t give three ****s about efficiency but what I do want is a truck that’s still around 300,000 miles from now.
My 2017 F550 last id driven was right under 560,000mi and still on the original transmission that runs about 230 degrees when hauling. I even do the 150,000mi fluid change interval. Thats just one of my high mileage trucks with original 6R transmission running hot.
Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
I have no claim on a high mileage 10R140 but do have quite the handful of 6R140 that run just as hot with well over 300,000mi. After my first hand experience with the 6R I cant but help to speculate that Ford understands what they are doing with the 10R.
My 2017 F550 last id driven was right under 560,000mi and still on the original transmission that runs about 230 degrees when hauling. I even do the 150,000mi fluid change interval. Thats just one of my high mileage trucks with original 6R transmission running hot.
My 2017 F550 last id driven was right under 560,000mi and still on the original transmission that runs about 230 degrees when hauling. I even do the 150,000mi fluid change interval. Thats just one of my high mileage trucks with original 6R transmission running hot.
Logistics Pro
Joined: May 2022
Posts: 4,285
Likes: 2,416
From: Everywhere and nowhere
I think that’s what I’m trying to get through to folks here even that fluid is gonna start burning up at 260° sustained. You don’t have any overhead and Sure if the truck is brand new under warranty. You’re probably gonna be fine but there’s a good chance you’re not gonna be fine down the road. And as we have found, Ford is more than happy to sell you a $14,000 transmission. And part of the fix a simple that speeds under 50 in my truck with a 430 rear lockout ninth and 10th gear and the problem is literally solved. Kind of like the old E4OD days. Get that that thing out of overdrive when you’re slow towing and lugging. 90% of those transmissions could’ve been saved from doing that one thing. But there were people on the forums then too saying the same BS if they didn’t want you to use overdrive, they wouldn’t have put it on the stick. Of course they had bad valve bodies and a bunch of other nonsense wrong with them, but still could’ve been saved.
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Cross-Country
Joined: Jan 2022
Posts: 83
Likes: 26
No one is claiming their 10R runs 260F on any forum I've read. Also the 10R140 isn't a $14000 transmission. The 10R140 coolant control valve for co trolling the fluid temp kinda like the E40D which had a trans cooler built into the radiator? Like when you were towing in 100F and the trans is working overtime you need the coolant to control the trans temp? You are arguing 30 year old transmission tech against a modern fluid designed to operate at a higher temp. You self-admittadely don't work at the family transmission shop but are acting like the E40D technology is still relevant with fluid designed for these modern 1pspd transmissions. Move on.
Cargo Master
Joined: Mar 2021
Posts: 2,044
Likes: 1,336
No one is claiming their 10R runs 260F on any forum I've read. Also the 10R140 isn't a $14000 transmission. The 10R140 coolant control valve for co trolling the fluid temp kinda like the E40D which had a trans cooler built into the radiator? Like when you were towing in 100F and the trans is working overtime you need the coolant to control the trans temp? You are arguing 30 year old transmission tech against a modern fluid designed to operate at a higher temp. You self-admittadely don't work at the family transmission shop but are acting like the E40D technology is still relevant with fluid designed for these modern 1pspd transmissions. Move on.
and with the new 10speeds in the gm hd trucks experiencing issues I’m not sure how they’re any better just because they run at a cooler temp if they’re still having more actual issues than the fords. Excluding aisin we won’t even begin to compare the strength and durability of ram’s 6speed versus the ford transmissions.
Cargo Master
Joined: Apr 2018
Posts: 2,403
Likes: 1,123
I have no claim on a high mileage 10R140 but do have quite the handful of 6R140 that run just as hot with well over 300,000mi. After my first hand experience with the 6R I cant but help to speculate that Ford understands what they are doing with the 10R.
My 2017 F550 last id driven was right under 560,000mi and still on the original transmission that runs about 230 degrees when hauling. I even do the 150,000mi fluid change interval. Thats just one of my high mileage trucks with original 6R transmission running hot.
My 2017 F550 last id driven was right under 560,000mi and still on the original transmission that runs about 230 degrees when hauling. I even do the 150,000mi fluid change interval. Thats just one of my high mileage trucks with original 6R transmission running hot.
I clipped a deer with it, took out passenger side headlight, bumper being with the bed rusting it was time to sell it off. I wanted to invest back into but the bean counters thought otherwise.
I actually missed that truck, but what does this clown know?
In my fleet, since 2017 we replaced as far as a major components
F650's engine, 2 turbos
550's one turbo
450's, We don't have any
350's. One CP4
250's transfer case and differential.
F150's 2 transmission's, one of them twice
My 2022 Raptor transmission lasted 200 miles
My Transit, Don't even want to talk about those pieces of junk.
Cross-Country
Joined: Dec 2024
Posts: 71
Likes: 51
I used to be in the camp that higher trans temps were very bad and would cause premature failure, but I just don't think that's the case anymore from my experiences. I had a 2017 tundra that ran 200-225 consistently and towed every day and I never had an issue with that transmission. Sold It to a buddy of mine and its still chugging along. Both of my GM HD trucks I had, a 2016 and a 2023 both ran cooler temps and both had transmission issues. The 16' was the 6l90 and ran 160-176 pulling and it ate the convertor at 55k miles and took the trans out, my 23' 10l1000 was the coolest running transmission I've ever at. That truck would run 150-160* under load, never saw anything higher and at about 6500miles she had to come out for an issue. With all the Valve body issues popping up on the GM forum I was on Running the fluid at a cooler temp must not be the magic bullet we thought it once was.
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kehinnc
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Apr 28, 2023 11:10 AM