Transmission cooling-can it be improved?

[duneslider]

Alright, I finally got around to replacing the thermostat in my 2020 with hopes it would help keep the transmission temp lower when towing. On a recent trip to Lee Canyon area just outside of Vegas, the trans got really hot and I had to pull over and sit on the side of the road for an hour to let it cool off. It saw 240 degrees, this is the worst I have experienced, and I was pretty disappointed. Regular towing on the highway seemed to have a temp that floats around 214-223.

Anyway, I replaced the thermostat like others on here have done and had hoped that would help things. I did have the old style, all metal. I put the new one in and am not certain it is making any difference. I towed again this weekend in upper 80 degree temps, not as much climbing as the previous weekend though. I still saw temps in the 214-220 range over this trip.

Trailer is a rockwood roo 233s, I don't weigh it every trip but it would be under 7000#'s. I'm also not flogging it. I drive fairly conservative at 65-70 (speed limit is 80 through most the area I travel) and don't hammer it on the hills or anything. I have tried going a little slower and that doesn't seem to make much difference, heat shows up when it is in the boost and its just gonna be in the boost when going up hill.

I haven't seen much more on the forum here about what else people have done to address this issue. Some have added the PPE aluminum pan, which I am considering but others results seem to show that may not have made much if any difference either. It seems the issue is the coolant to oil heat exchanger, which means the trans will never be cooler than the engine and there is always potential for heatsoak to happen.

On the F150/raptor forums I am seeing they have been changing to oil to air coolers and getting good results with temps. Here is one adaptor they seem to be using. Cooler Adapter Any chance anyone has tooking into this? I need to change the oil in mine and I am planning to look at the trans and see what the routing looks like currently. I am guessing with that adapter they are getting rid of the current heat exchanger completely and just using an air to oil cooler.

I am not a transmission expert, what concern (if any) is there with a trans temp that is lower and not heating up like the current one does? I have always been told the higher temps were for emissions reasons. Do I have concerns about temps being too low in the winter?

Would an intercooler help with temps at all? I know they are just combustion air but maybe if the engine is running cooler/better? Probably not really an answer for this? Lower grill shutters, get rid of them they are a waste and not helping anything? Will this maybe help at all? Honestly, I bought the expedition to carry the family and tow, I will probably dump the expedition in a couple years when I don't have as many people to carry if I can't figure this out. From what I read, the GM 10r80 variant runs at 160-180 deg and uses and air to oil cooler.

 

[HILLY]

On my previous Expy before it was totaled I had physically installed a Mishimoto F-150 trans cooler. I never did get around to getting it plumbed up. Believe it or not I went to a couple of transmission places to get a service done plus have this plumbed up but they all got cross eye over the thought of the job. Aside from getting the bumper off it wasn't hard to mount.

Lower temp T-stat is a start. I'm in the south so I went with a 170* unit and I hardly see temps go over 200*. Norms are around 180*-185* at temp. It still gets cold here in GVL with with temps dipping in the teens, but never had an issue getting up to temp and maintaining.

I also gutted out the air shutters in the upper and lower grills. I drove around with a scan tool reading the status of these and unless you're running max A/C, they stay closed more often than not, even in the heat of summer. This helped a lot.

Intercooler is definitely worthwhile as it will stabilize temps. Always hear positives about them, not much negatives.

Transmissions do need to get warm, but I'm also a firm believer that they are running hotter than they need to be. A cooler with definitely help regulate that especially when towing. You can run a cooler after the fluid runs through the heat exchanger to get it up to temp and then it's managed.

@Silver-Bullet-Bus from what I understand is a tower has done a lot to improve the efficiency of his ride to both tow and compensate for the power mods done.

 

[duneslider]

On my previous Expy before it was totaled I had physically installed a Mishimoto F-150 trans cooler. I never did get around to getting it plumbed up. Believe it or not I went to a couple of transmission places to get a service done plus have this plumbed up but they all got cross eye over the thought of the job. Aside from getting the bumper off it wasn't hard to mount.

Lower temp T-stat is a start. I'm in the south so I went with a 170* unit and I hardly see temps go over 200*. Norms are around 180*-185* at temp. It still gets cold here in GVL with with temps dipping in the teens, but never had an issue getting up to temp and maintaining.

I also gutted out the air shutters in the upper and lower grills. I drove around with a scan tool reading the status of these and unless you're running max A/C, they stay closed more often than not, even in the heat of summer. This helped a lot.

Intercooler is definitely worthwhile as it will stabilize temps. Always hear positives about them, not much negatives.

Transmissions do need to get warm, but I'm also a firm believer that they are running hotter than they need to be. A cooler with definitely help regulate that especially when towing. You can run a cooler after the fluid runs through the heat exchanger to get it up to temp and then it's managed.

@Silver-Bullet-Bus from what I understand is a tower has done a lot to improve the efficiency of his ride to both tow and compensate for the power mods done.

I found that post, I had forgotten about it, I had looked into this with my previous expedition that was also totalled. I am going to look into doing the cooler like @Silver-Bullet-Bus did. I also am going to figure out what I need to do to gut the air shutters, those seem like they aren't helping me at all. If I am going to tear into everything to do the transmission cooler maybe I do an intercooler at the same time.

 

[5280tunage]

I found that post, I had forgotten about it, I had looked into this with my previous expedition that was also totalled. I am going to look into doing the cooler like @Silver-Bullet-Bus did. I also am going to figure out what I need to do to gut the air shutters, those seem like they aren't helping me at all. If I am going to tear into everything to do the transmission cooler maybe I do an intercooler at the same time.

luckily, from experience, the intercooler doesn't require any bumper or grill work. it's all easily done from underneath.

 

[Fastcar]

You may be better served with a deeper pan. Xtra capacity should buy maybe 10 degrees.

 

[duneslider]

You may be better served with a deeper pan. Xtra capacity should buy maybe 10 degrees.

Unfortunately, with the way the cooling system is done on the expedition it will never be lower than the ECT. It is cooled/heated with coolant straight from the engine...
Unless you have an external way of cooling the oil it will be near the coolant temp when operating.

 

[HILLY]

I found that post, I had forgotten about it, I had looked into this with my previous expedition that was also totalled. I am going to look into doing the cooler like @Silver-Bullet-Bus did. I also am going to figure out what I need to do to gut the air shutters, those seem like they aren't helping me at all. If I am going to tear into everything to do the transmission cooler maybe I do an intercooler at the same time.

Shutters require removal of the bumper/grille. After that it’s very easy. Just pop them out of their plastic bracket.

Nothing else done. No check engine light but I do have a soft code for the actuator out of range.

As far as the cooler, I’ll probably tackle that again. Just need to find a shop willing to be creative. Not sure if I’d remove the HX or plumb it in after it.

 

[duneslider]

Shutters require removal of the bumper/grille. After that it’s very easy. Just pop them out of their plastic bracket.

Nothing else done. No check engine light but I do have a soft code for the actuator out of range.

As far as the cooler, I’ll probably tackle that again. Just need to find a shop willing to be creative. Not sure if I’d remove the HX or plumb it in after it.

I don't see leaving the HX making things much better. The guys on the raptor forum that have the different setup are still having issues with hot transmissions due to the HX. Now, the raptor setup might work fine on the expedition. I just don't see a good way to put the cooler in after the HX, not a lot of pipe to do it and make it work. It sounds like on the raptor there is some sort of valve or thermostat on the raptor that has to be bypassed to get them to run cool.

On my jeep I plumbed in a transmission cooler after the factory cooler (factory is in the bottom of the radiator) and it is pretty effective but it is a lot different setup than the ford.

 

[Joe S]

I have a 2012 Limited with heavy duty tow package...I replaced my stock 5 core cooler with a OEM Ford Raptor 10 core cooler and its a easy swap using the same bracket...easy upgrade....

 

[Joe S]

Oh fyi..I found out about this swap because Ford was shipping Ford Raptor trucks to Saudi Arabia and they needed extra cooling from the bigger core trans cooler because of the brutal heat over there

 

[HILLY]

On my jeep I plumbed in a transmission cooler after the factory cooler (factory is in the bottom of the radiator) and it is pretty effective but it is a lot different setup than the ford.

I did a very similar install on my old 4Runner with good results. Why I also contemplated this on this truck as well. It’s not a bad thing to get it up to a decent operating temp quickly. Just keeping it cool after the fact.

I know mishimoto makes the thermostat bypass valve as well. Sounds like the ford unit can be problematic and get stuck not allowing fluid to pass through the cooler. But their plumbing is completely different than the expeditions.

 

[Rednecked]

Shutters require removal of the bumper/grille. After that it’s very easy. Just pop them out of their plastic bracket.

Nothing else done. No check engine light but I do have a soft code for the actuator out of range.

As far as the cooler, I’ll probably tackle that again. Just need to find a shop willing to be creative. Not sure if I’d remove the HX or plumb it in after it.

IC shutters don’t require you to remove the bumper etc… drop the intercooler from underneath and pull the shutters. Easy….

Upper radiator shutters well…… thats prolly a day worth of work removing the front end.

 

[HILLY]

IC shutters don’t require you to remove the bumper etc… drop the intercooler from underneath and pull the shutters. Easy….

Upper radiator shutters well…… thats prolly a day worth of work removing the front end.

Good to know. But if you're going to do one, why not the other. I can have the bumper off in 15 minutes, so probably not much difference for the IC R&I.

 

[duneslider]

okay, how do I gut the shutters without it throwing codes? Is there any reason besides fuel efficiency that the shutters make sense?

I'm not terribly concerned with fuel efficiency...this is the most fuel efficient vehicle I have ever owned...

 

[duneslider]

I have a 2012 Limited with heavy duty tow package...I replaced my stock 5 core cooler with a OEM Ford Raptor 10 core cooler and its a easy swap using the same bracket...easy upgrade....

The 2012 cooling system is nothing like the Gen 4 cooling system. The Gen 3 was a much better setup than the Gen 4.

 

[HILLY]

okay, how do I gut the shutters without it throwing codes? Is there any reason besides fuel efficiency that the shutters make sense?

I'm not terribly concerned with fuel efficiency...this is the most fuel efficient vehicle I have ever owned...

You're not going to throw any codes that will inconvenience you. No check engine light. At least not in my case. Might throw a shop tech off after doing a code scan and doesn't realize what has been done. I did leave a shutter in place where it mounts to both the radiator and IC actuators, but it still doesn't limit it enough to where it throws a soft code.

It's twofold for what it is to accomplish:
1. To block off airflow to get the engine hot as quickly as possible (emissions).
2. The minimizing of air flow through the engine provides some mileage efficiency.

There's a few cases where you can see performance trumps these setups. Look at a normal BMW vs an M car (i.e. X5 vs X5M). The X5M doesn't have any shutters in the grilles and is setup for max efficiency for cooling.

 

[Rednecked]

Good to know. But if you're going to do one, why not the other. I can have the bumper off in 15 minutes, so probably not much difference for the IC

Good to know. But if you're going to do one, why not the other. I can have the bumper off in 15 minutes, so probably not much difference for the IC R&I.

15mins?? Come over….. lol

 

[chuck s]

No solutions based on my similar truck and trailer -- but wildly different terrain.

Was curious but not concerned about my transmission temperatures so over Memorial Day I compared my 2017 Expedition XLT 3.5EcoBoost normal transmission temperature (not towing) with towing with my Roo 23SS on the back and there was basically no difference. 190°F to maybe 203°. Pretty constant just below 200°. Virginia not Arizona though. HD Tow/Haul On or Off also seemed to make no discernible difference. Didn't pay close attention last summer in the mountains here but will the next time.

Please keep us up to date on other solutions.

-- Chuck

 

[Mr Big]

For reference purposes, my Expedition Platinum with the heavy duty tow package, here in Tampa Bay Florida, has a coolant temp of 190 to 205 and a tranny temp of 182 to 190. Both were higher, (coolant 212, tranny 208), before my dealership performed software updates to the pcm and tcm modules.

 

[duneslider]

For reference purposes, my Expedition Platinum with the heavy duty tow package, here in Tampa Bay Florida, has a coolant temp of 190 to 205 and a tranny temp of 182 to 190. Both were higher, (coolant 212, tranny 208), before my dealership performed software updates to the pcm and tcm modules.

Struggling to make sense of that, not sure what reprogramming would do to change that? I do have a recall that needs to be done so maybe I will talk to them when I take it in and see if there are any updates that need to be done. What was the reason you have the pcm/tcm updated?