Oil temp concerns

**bertschb** · 06-05-2021, 11:06 AM

Originally Posted by Redapple63

I know the 10 speed was supposed to be a joint Ford/GM venture,

The joint venture was for the light duty 10-speed, not the new 10 speed in the Superduty.

**Redapple63** · 06-05-2021, 12:02 PM

Originally Posted by bertschb

The joint venture was for the light duty 10-speed, not the new 10 speed in the Superduty.

Thanks for the clarification Brian.

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**SummitJim** · 06-06-2021, 02:01 PM

Thank you all for your input. I do love this engine and transmission. If my truck were painted blue I would call him Babe the Blue Ox! So I will still keep an eye on the temp climbing the Grapevine but will enjoy the ride.

**MoonShadow_1911** · 06-06-2021, 07:03 PM

Originally Posted by SummitJim

So we have a new 2020 F250 with 6.7 L diesel and 10 speed transmission. Next month we will be towing our 320MKS (about 13,000 lb loaded) to Phoenix from Northern California. So far the engine and transmission oil temps range up to about 190 degree but we will be climbing the Grapevine and then running I-10 in Arizona where the outside temps may hit or exceed 100 degrees. I don't plan to run the engine up to its maximum ability anyway but I'm wondering 1) should I just let the truck do what it wants in tow/haul mode, or manually gear down a bit more on that big hill. And 2) how hot can the transmission get before Ishould be concerned? Should I expect issues, or just a happy truck?
Thanks.

Okay, some very recent, real world, data.

I drove from Albuquerque to Van Horn, TX with the high outside temps ranging from 95°-100°. The engine temp never went about 218°, but the transmission temp went as high as 226° for about 10 minutes. I was in Tow/Haul mode with the exhaust brake on for the hills. I do watch the temps and do my best to keep them below 215°.

This was pulling my 320MKS at 70 MPH, with cruise control, so I wouldn't speed. (I'm a serious lead foot!)

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**huntindog** · 06-06-2021, 07:29 PM

Originally Posted by Redapple63

I can completely understand coming from the 6 speed. My 2019 Duramax with the Allison typically runs 165 empty, 180 or so under heavy load, maybe really hot for me is around 190. Could certainly understand coming from an older truck that ran so much cooler. Seems the new 10 speeds run hotter. Not sure if that is the same for the GM vehicles. I know the 10 speed was supposed to be a joint Ford/GM venture, but I also heard that each decided to implement their own firmware which could make the same mechanicals vastly different )my perspective from owning three GM’s with Duramaxes, never owned a Ford.

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I am on my 3rd Dmax. The 2020 runs cooler than any of the previous ones. Right around 160 degrees. So, no a 10 speed doesn't have to run hot.

**huntindog** · 06-06-2021, 07:35 PM

Originally Posted by SummitJim

So we have a new 2020 F250 with 6.7 L diesel and 10 speed transmission. Next month we will be towing our 320MKS (about 13,000 lb loaded) to Phoenix from Northern California. So far the engine and transmission oil temps range up to about 190 degree but we will be climbing the Grapevine and then running I-10 in Arizona where the outside temps may hit or exceed 100 degrees. I don't plan to run the engine up to its maximum ability anyway but I'm wondering 1) should I just let the truck do what it wants in tow/haul mode, or manually gear down a bit more on that big hill. And 2) how hot can the transmission get before Ishould be concerned? Should I expect issues, or just a happy truck?
Thanks.

I have lived in Phoenix for 50 years. You are underestimating the temps here. In July It WILL be over 100 degrees. It will probably be 110 or higher, and it is not uncommon to see 115 or more

**bertschb** · 06-06-2021, 07:37 PM

Originally Posted by huntindog

So, no a 10 speed doesn't have to run hot.

I don't think anybody has said 10 speed transmissions have to run hot. What we're saying is the new Ford 10 speed transmission in the Super Duty runs hotter than the prior generation 6 speed. Ford designed it to operate at these higher temperatures and that is normal for this Ford transmission which is what the OP was asking about.

**huntindog** · 06-06-2021, 08:12 PM

Originally Posted by bertschb

I don't think anybody has said 10 speed transmissions have to run hot. What we're saying is the new Ford 10 speed transmission in the Super Duty runs hotter than the prior generation 6 speed. Ford designed it to operate at these higher temperatures and that is normal for this Ford transmission which is what the OP was asking about.

There is NO advantage in designing a tranny to run hot... In fact just the opposite is true. Now engines have been designed to run hotter nowadys, mainly for emissions reasons.
The Ford has weak tranny cooling in the current model.... FWIW, GM was weak in that area in the past. A lot of aftermarket tranny cooler companies made quite a bit of profit from GM owners around 2006.

Oh yeah, read Redapples post again about 10 speeds running hotter

**bertschb** · 06-06-2021, 08:19 PM

Originally Posted by huntindog

There is NO advantage to designing a tranny to run hot...

Nobody here has said there is an advantage to running hot. The ONLY thing we're trying to communicate is that the new Ford 10 speed transmissions in their Super Duty trucks run hotter than the prior 6 speed. The reason we are posting this information is because the OP was voicing concerns over temps while towing over passes on hot days - with a 10 speed Super Duty transmission.

**Redapple63** · 06-06-2021, 09:10 PM

Originally Posted by Redapple63

I can completely understand coming from the 6 speed. My 2019 Duramax with the Allison typically runs 165 empty, 180 or so under heavy load, maybe really hot for me is around 190. Could certainly understand coming from an older truck that ran so much cooler. Seems the new 10 speeds run hotter. Not sure if that is the same for the GM vehicles. I know the 10 speed was supposed to be a joint Ford/GM venture, but I also heard that each decided to implement their own firmware which could make the same mechanicals vastly different )my perspective from owning three GM’s with Duramaxes, never owned a Ford.

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Here is what I said. It is based on what is read here. I also said I never owned a Ford, so again based on what was said here and I provided my GM experience. Bottom line is that most so far that have spoken here have said theirs run hotter than the 6 speeds. Seems like you have had a different experience with your truck, which is fine. We would like to hear more about your experience.

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