External Transmission Cooler??

[Thomas Warden]

Does my 2019 XLT have a external transmission cooler?? I have the standard tow package (not HD tow package). Getting ready to tow a approx. 5000 lb camper. Should I add an external transmission cooler, or do I really need one??

 

[yellowlight]

Nope. I don't add a transmission cooler. Expedition is also made for towing but maybe if you would just tow let's say 9000 lb.

 

[Thomas Warden]

I wish my XLT had the Heavy Duty tow package, but it doesn't. 6,000 lb max with 600 lb. tongue weight is what I'm dealing with . Just didn't want to damage the transmission.

 

[Going_Going_Gone]

From what I've read, the newer automatic transmissions run much hotter than what has been the norm; and the fluids are capable of withstanding the higher temps. I've also read that flow to the coolers is "thermostatically regulated" to maintain the higher operating temps, so flow rate to the stock cooler can be variable, even when towing. I went with the HD towing pkg. primarily for the 3.73 ratios, integrated trailer brake controller, and the two-speed transfer case.

 

[duneslider]

Auto Transmissions are super complicated pieces of machinery. They need the fluid to be up to a certain temp to work correctly. Some will even limit the gears available until that temp threshold has been met. That said, too hot and it cooks the seals and ruins the fluid and its a big problem. I have never talked to a single transmission shop that said an extra cooler is a bad idea. It may not be necessary but it isn't a bad idea. If you are working the transmission hard the faster and more efficiently it can cool down the better. The pumps do regulate the flow but once it starts flowing the quicker it can cool down the better. The fluid itself can handle extra heat, things get really hot in the torque converter but if the temps seen in the converter were seen in the pan and the rest of the transmission there would be problems. I have seen the temps in my cooler climb higher than made me comfortable (towing 5k up a steep grade at under 25) Once I hit dirt road I put it in 4lo and the temps dropped almost instantly. I have not seen any issues with temps when towing at higher speeds on the highway. Here in Utah Parley's Canyon in the summer is a long hot steep grade and every vehicle I have towed with prior to the expedition got a little hot going up it but the expedition didn't get hot at all.

An additional cooler will not hurt the transmission. It may not be totally needed but it won't hurt. I may look into one depending on what I observe over next summer's towing.

Make sure you use the tow haul mode, it does change how the transmission works.

 

[8131full]

Auto Transmissions are super complicated pieces of machinery. They need the fluid to be up to a certain temp to work correctly. Some will even limit the gears available until that temp threshold has been met. That said, too hot and it cooks the seals and ruins the fluid and its a big problem. I have never talked to a single transmission shop that said an extra cooler is a bad idea. It may not be necessary but it isn't a bad idea. If you are working the transmission hard the faster and more efficiently it can cool down the better. The pumps do regulate the flow but once it starts flowing the quicker it can cool down the better. The fluid itself can handle extra heat, things get really hot in the torque converter but if the temps seen in the converter were seen in the pan and the rest of the transmission there would be problems. I have seen the temps in my cooler climb higher than made me comfortable (towing 5k up a steep grade at under 25) Once I hit dirt road I put it in 4lo and the temps dropped almost instantly. I have not seen any issues with temps when towing at higher speeds on the highway. Here in Utah Parley's Canyon in the summer is a long hot steep grade and every vehicle I have towed with prior to the expedition got a little hot going up it but the expedition didn't get hot at all.

An additional cooler will not hurt the transmission. It may not be totally needed but it won't hurt. I may look into one depending on what I observe over next summer's towing.

Make sure you use the tow haul mode, it does change how the transmission works.

What temps did you see? My temps climb quickly when towing going slow up a dirt road. Thinking about additional cooling as well.

 

[duneslider]

I didn't know that the expedition told the temp until after it had cooled back down. I wish i would have checked. by the time I knew it had a read out it was showing 225 but the gauge was moving up towards the "yellow" (whatever that means) before I put it in 4lo.

Anyway, this last week while towing it seemed to hover in the 218-220 range a lot which is hotter than my jeep commander with the hemi sat at while towing. I haven't towed slowly up steep roads since that time. I pulled several miles on dirt roads in moab this last weekend going pretty slow and never saw it over 220 but I wasn't going up any hills either, a little ups and downs but nothing a big deal.

What have you seen the temp get to on slow dirt roads?

 

[Artie]

I didn't know that the expedition told the temp until after it had cooled back down. I wish i would have checked. by the time I knew it had a read out it was showing 225 but the gauge was moving up towards the "yellow" (whatever that means) before I put it in 4lo.

Anyway, this last week while towing it seemed to hover in the 218-220 range a lot which is hotter than my jeep commander with the hemi sat at while towing. I haven't towed slowly up steep roads since that time. I pulled several miles on dirt roads in moab this last weekend going pretty slow and never saw it over 220 but I wasn't going up any hills either, a little ups and downs but nothing a big deal.

What have you seen the temp get to on slow dirt roads?

Having just ordered a 4500 pound overland trailer all this talk has me concerned.

 

[Wayne Decker]

If the vehicle is rate to tow 6K as equipped, you'd be fine towing 5k.

 

[duneslider]

Having just ordered a 4500 pound overland trailer all this talk has me concerned.

No issues at all on the highway at normal speeds but if you are climbing steep roads at under 25mph in 90+ degree weather it might be an issue. If it is dirt then just put it in 4lo and you will be totally fine. The only issue I encountered was stuck behind a slow truck going 20mph up a really steep road.

 

[Artie]

No issues at all on the highway at normal speeds but if you are climbing steep roads at under 25mph in 90+ degree weather it might be an issue. If it is dirt then just put it in 4lo and you will be totally fine. The only issue I encountered was stuck behind a slow truck going 20mph up a really steep road.

Good to know. We rarely camp in the heat but now that we’ll have a much better shelter I’m sure this will change. Thanks for the tips.

 

[duneslider]

Make sure to get the big generator if you camp in the heat, the AC takes more than the little honda 2000 will handle.

Last week we went from Salt Lake to Capital Reef then on to Moab and Dead Horse Point and back home and had no issues towing and the expedition did fantastic. We camped in the camp ground at capital reef (highly recommend, especially if you have kids) and we "roughed it" in Moab.

Nothing we encountered during this trip was an issue for the expedition, in fact, I am happier with it every time I tow.

 

[8131full]

What have you seen the temp get to on slow dirt roads?

245deg. Ugh... What does 4lo help? Tow mode puts it in 4auto, no?

 

[Artie]

If the vehicle is rate to tow 6K as equipped, you'd be fine towing 5k.

The weight on paved roads isn’t what has me concerned, it’s the off pavement slow rough terrain driving.

 

[Artie]

Make sure to get the big generator if you camp in the heat, the AC takes more than the little honda 2000 will handle.

Last week we went from Salt Lake to Capital Reef then on to Moab and Dead Horse Point and back home and had no issues towing and the expedition did fantastic. We camped in the camp ground at capital reef (highly recommend, especially if you have kids) and we "roughed it" in Moab.

Nothing we encountered during this trip was an issue for the expedition, in fact, I am happier with it every time I tow.

So everything on our rig runs off solar and lithium batteries except for the ac, that only requires 2k watts. We have plans for Moab and the general southwest area. My wife’s family is in Albquerque so we have a good layover place there so we can do a month out once a year.

 

[duneslider]

I doubt the honda 2000 will power the AC, I suspect the start up on the AC will exceed 2k. You will probably need 2 hondas or a bigger 3k generator.

 

[duneslider]

245deg. Ugh... What does 4lo help? Tow mode puts it in 4auto, no?

Tow doesn't put in 4auto, unless you select it. 4lo gives you the benefit of gear reduction and reduces the load on the engine transmission. I pulled slow and up really steep roads in 4lo and the temp stayed lower than towing on the road at highway speeds.

245 is getting hot but isn't enough to destroy stuff. I really do think I will want to add a transmission cooler in the future. I should probably start looking at options. I knew some guys who added Derale Heat Sink fluid coolers to their jeeps with fans and said they have good results with them. This allowed them to not have to put them in the air flow through the front of the jeep. I haven't looked at the cooler on the expedition to know what it is like. ON the jeep JK it isn't a good cooler and really isn't adequate for offroad.

 

[duneslider]

So everything on our rig runs off solar and lithium batteries except for the ac, that only requires 2k watts. We have plans for Moab and the general southwest area. My wife’s family is in Albquerque so we have a good layover place there so we can do a month out once a year.

What trailer did you get? Sounds like a nice rig!

 

[8131full]

Tow doesn't put in 4auto, unless you select it. 4lo gives you the benefit of gear reduction and reduces the load on the engine transmission.

Thanks, I'll try that next time coming up the hill. Funny (and I posted this before), the 'analog' gauge on the dash never moved passed middle at all, but watching the 'digital' read out of the temps shows those high temps.

 

[Artie]

I doubt the honda 2000 will power the AC, I suspect the start up on the AC will exceed 2k. You will probably need 2 hondas or a bigger 3k generator.

It works fine with the Yamaha generator I have as I saw it run the same rig I’m getting . This isn’t a traditional RV so I’m assuming it’s a smaller AC unit, it requires 2k watts and my Yamaha is a 2200 max.