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.