Transmission Cooler Worth It?

[Shiny]

Anyone have experience with an aftermarket trans cooler for a 2018 Chevy Silverado 1500/5.3 gas?

Chevy does not offer an "add-on" cooler and the dealer parts dpt recommended a "Mishimoto" brand that's $450 plus labor to install!! I don't see a lot of options online. The dealer said it is not a typical issue nor concern which is why there is no Chevy-branded "upgrade" available.

We had an "overtemp event" while towing our 5.0 last summer up McClure Pass at altitude (~8500 ft). The truck's temp monitor was showing hot enough to be a concern but not a crisis. This happened when we got stuck behind a dump truck for a few miles on a moderate grade. We simply didn't have enough speed for airflow to keep the fluid within "normal" range and the fan didn't get it done either.

I'm on the fence about it, given the cost and this being the only time it happened... but I also don't want the transmission to fail nor do I want to worry about it.

Anyone have the same truck and face a similar decision?

[HABBERDABBER]

There's plenty of aftermarket tranny coolers out there. It's typically a straight forward installation any shade tree mechanic can do. If you have space in front of your regular radiator, it's usually just a connect the tubing process. It's just a small radiator. The tranny fluid is typically cooled thru your existing radiator, but with only a few dinky coolant tubes, if that. A tranny cooler adds the small and effective radiator. The input and output tubing is very nearby there, already.

A tranny rebuild can cost $$thousands$$. Having one is prudent insurance. Look around. They often cost $100 or less, as a kit.

Cost/benefit ratio? Very high benefit to add one. Very high potential cost not to.

[Iowa Dave]

I installed transmission cooler kits on three of my vehicles years ago. One after the cooling system became hot when I got stuck behind a bus. That time I stopped at a pullout, turned the AC off, turned the heater on to add more coolant circulation and manually ran the engine at a fast idle. The temp went down and we proceeded up the grade. A mile or so later the bus was pulled over and stopped, overheated. It was the first summer I’d had the vehicle and when I got home I put a cooler on the vehicle. I was pulling a big fold down trailer. Never had any additional trouble. After putting coolers on three vehicles, I only bought vehicles with factory coolers on them. When there was more than one size I always bought the largest one recommended.
They worked for me.
Iowa Dave

[Shiny]

Originally Posted by HABBERDABBER

There's plenty of aftermarket tranny coolers out there. ...A tranny rebuild can cost $$thousands$$. Having one is prudent insurance. Look around. They often cost $100 or less, as a kit...Cost/benefit ratio? Very high benefit to add one. Very high potential cost not to.

Sounds good. I do see some "generic" coolers under $100 and will look at the reality of installation, connections, materials, and warranty. I understand it's just a radiator but I also understand the quality can suffer when building the lowest cost. I suspect it would be easy to end up with "universal" rubber lines that don't last.

I thought it odd Chevy did not offer a cooler because my truck is not equipped with a "towing package". If it had been, I would have gotten a lower rear ratio and a brake controller integrated with the truck's ABS system. But it would NOT have added increased transmission cooling. This was a surprise to me.

Originally Posted by Iowa Dave

I installed transmission cooler kits on three of my vehicles years ago. ....After putting coolers on three vehicles, I only bought vehicles with factory coolers on them. When there was more than one size I always bought the largest one recommended.
They worked for me.
Iowa Dave

Thank you. I've got some shopping to do.

[Great Eggstrications]

Originally Posted by Shiny

We had an "overtemp event" while towing our 5.0 last summer up McClure Pass at altitude (~8500 ft). The truck's temp monitor was showing hot enough to be a concern but not a crisis.

Just curious...

How hot did your monitor show? One would think that a full-size pickup would have plenty of tranny cooling capacity as standard equipment.

We were having an ATF over-temp issue on our 4Runner (which admittedly isn't exactly intended to be a towing workhorse). Toyota rates the vehicle good for 5,000 lbs towing, but they don't bother to mention that if you tow much of anything, especially on a hot day and/or up much of a grade, before long you're looking at 230+ degrees and rising. Installing a A B&M 70264 14,400 BTU cooler in series with the factory ATF cooler built into the coolant radiator greatly helped, but we still run into problems once in a while, e.g. late last June we were trundling up 89 from the east in 100+ degree heat stuck behind a very slowly moving semi truck, and the ATF was 235 and rising fast. We stopped at Jacobs Lake Junction and sat at fast idle in neutral till it got cooled back down.

The 4Runner has an over-temp idiot light, but it apparently doesn't come on till you hit 302 degrees, and by then (according to the general consensus on the interwebs) the damage has already been done. Thank goodness for ScanGauge and the Torque Pro phone app. We still have to keep an eye on things. Even on a temperate day, going up a long gradual grade can be problematic. It helps to keep the torque converter locked and keep the revs up to keep the ATF circulating pump spooled up - that right there drops the temp 20 degrees almost immediately.

The cooler install was pretty much of a bonehead project - the worst part was fabricating mounting brackets to fit it in the confined space in front of the radiator and A/C condenser. The cooler came with a remarkably cheezy mounting method: Nylon zip-ties that you were supposed to thread through the fins of the radiator and condenser and cooler, clamping the cooler hard up against the front of the condenser. OUCH! They gotta be kidding, but they weren't.

[HABBERDABBER]

There are stainless steel zip ties sold all about. They'll work, not affected by heat under the hood. If you're fastidious, fab some proper mounts. But until you do, get the tranny cooler installed. It's a help, biggly. Your credit card will be pleased.

[Shiny]

Originally Posted by Great Eggstrications

Just curious...

How hot did your monitor show? One would think that a full-size pickup would have plenty of tranny cooling capacity as standard equipment.

We were having an ATF over-temp issue on our 4Runner (which admittedly isn't exactly intended to be a towing workhorse). Toyota rates the vehicle good for 5,000 lbs towing, but they don't bother to mention that if you tow much of anything, especially on a hot day and/or up much of a grade, before long you're looking at 230+ degrees and rising. Installing a A B&M 70264 14,400 BTU cooler in series with the factory ATF cooler built into the coolant radiator greatly helped, but we still run into problems once in a while, e.g. late last June we were trundling up 89 from the east in 100+ degree heat stuck behind a very slowly moving semi truck, and the ATF was 235 and rising fast. We stopped at Jacobs Lake Junction and sat at fast idle in neutral till it got cooled back down.

The 4Runner has an over-temp idiot light, but it apparently doesn't come on till you hit 302 degrees, and by then (according to the general consensus on the interwebs) the damage has already been done. Thank goodness for ScanGauge and the the Torque Pro phone app. We still have to keep an eye on things. Even on a temperate day, going up a long gradual grade can be problematic. It helps to keep the torque converter locked and keep the revs up to keep the ATF circulating pump spooled up - that right there drops the temp 20 degrees almost immediately.

The cooler install was pretty much of a bonehead project - the worst part was fabricating mounting brackets to fit it in the confined space in front of the radiator and A/C condenser. The cooler came with a remarkably cheezy mounting method: Nylon zip-ties that you were supposed to thread through the fins of the radiator and condenser and the cooler which would clamp the cooler hard up against the front of the condenser. OUCH! They gotta be kidding, but they weren't.

Thank you! This is useful. I appreciate the specifics. That guidance on mounting is what I might expect from a "generic" cooler and want to avoid.

As I recall, the temp hit over 250 but I honestly don't remember the details. The truck is rated to pull ~7000 lbs and in general, the cooling system works great as long as the vehicle is moving. I've seen the trans fluid heat fast when just maneuvering the trailer around our yard. I almost think a bigger fan would help as much as a cooler.

[Great Eggstrications]

Originally Posted by HABBERDABBER

There are stainless steel zip ties sold all about. They'll work, not affected by heat under the hood.

I wasn't particularly concerned about heat, but about the tranny cooler being clamped up against the condenser and the potential for metal-on-metal rubbing. Plus, I'd hate to have much of anything - nylon or stainless or whatever - threaded through the delicate fins of the coolant radiator and condenser and beating 'em up.

Originally Posted by HABBERDABBER

If you're fastidious, fab some proper mounts. But until you do, get the tranny cooler installed. It's a help, biggly. Your credit card will be pleased.

Amen to that!

[azjack]

Some 50 years ago we were headed up Sonora Pass in Ca., towing a travelezs 23' trailer when Nancy complained about smelling something. It was the transmission boiling the fluid so we turned around and went down hill and around through Las Vegas enroute to Colorado. In Vegas I stopped at a auto parts store and bought/installed a good sized cooler and we continued to Colorado. The vehicle was a Ford Ranchero V-8 and it towed that same trailer many more miles.
AZjack

[George Johnson]

Another reason to use an after market tranny cooler is that a number of automatic transmissions these days come from the factory as sealed units. Believe it or not, these transmissions cannot be serviced, and the customer is expected to run it until it breaks, then replace the unit or dispose of the vehicle.


I tow with a '17 Nissan Frontier, and my specialty transmission shop (confirmed by the dealer) says that without a drain plug, I cannot do a complete fluid flush, only about 50% of the fluid can be suctioned out and replaced at a time--the fluid in the torque converter remains behind. I'm informed other transmissions don't even have dip sticks to check fluid levels, they are completely sealed, just like the transmission in your riding lawn mower. You can be sure I change the fluid every 30k miles to extend the life of my tranny. Overheated transmission fluid is the primary cause of automatic transmission failure.


Go to www.etrailer.com and check out their inventory of transmission coolers. They probably even have a video showing you how to install the cooler in your specific vehicle. They have one for my '17 Nissan, and that is certainly not the most common tow vehicle on the road.

[Shiny]

Originally Posted by George Johnson

Another reason to use an after market tranny cooler is that a number of automatic transmissions these days come from the factory as sealed units. Believe it or not, these transmissions cannot be serviced, and the customer is expected to run it until it breaks, then replace the unit or dispose of the vehicle.


I tow with a '17 Nissan Frontier, and my specialty transmission shop (confirmed by the dealer) says that without a drain plug, I cannot do a complete fluid flush, only about 50% of the fluid can be suctioned out and replaced at a time--the fluid in the torque converter remains behind. I'm informed other transmissions don't even have dip sticks to check fluid levels, they are completely sealed, just like the transmission in your riding lawn mower. You can be sure I change the fluid every 30k miles to extend the life of my tranny. Overheated transmission fluid is the primary cause of automatic transmission failure.


Go to www.etrailer.com and check out their inventory of transmission coolers. They probably even have a video showing you how to install the cooler in your specific vehicle. They have one for my '17 Nissan, and that is certainly not the most common tow vehicle on the road.

Thanks for this info. I did not know. I have not yet reached the 1st service interval so haven't "learned" about this yet.

I have looked at etrailer and yes, there are lots of low-priced coolers. I looked at one manufacturer's site and they sell "remote" coolers with built-in fans. I like this idea, given my issue appears to be lack of airflow as much as cooling capacity. Probably makes sense for me to stop in a couple transmission shops and talk pros and cons about the options.

[dfandrews]

We were concerned about trans fluid temperatures in our Honda Pilot, towing our E17. So, we got a Scangauge II as a monitor. We discovered that our trans. temperatures were frequently in the 220°+ range when traversing climbs in the Eastern Sierra Nevada Mts., so we presume that that has been the case throughout travel in the Western U.S.
Our Honda Pilot has the factory tow package, with a two row trans cooler.
After some research, we purchased a Derale cooler kit from etrailer. (the largest that we had space for!) Our routine temperatures, now, even in the Mojave Desert, are in the 180-190° range (or lower). You can't really have too much radiating surface; lower temps. are best. The only caveat is that if you are climates with routine freezing, the very low temps. can be a problem.
Installation was straight forward. Once we removed the front fascia/grille (23 screws and fasteners; yuch!) for access, the install was per the instructions. The Derale cooler is plumbed in series and downstream from the factory cooler. We had purchased an extra 4 foot length of hose, and ended up using a portion of it.
So, based on our experience, we recommend a trans. cooler on your tow vehicle.
Edit: regarding the zip tie installation: bracket fabrication became problematic in a couple areas, space-wise, so I ended up using the zip tie method, per the kit instructions. There are pads to space the cooler away from the radiator, and with care to ensure that the hoses don't apply shear stress from being pulled tight, it is a firm, but non-hazardous installation.

[Shiny]

We had another "overtemp event" so I've decided to bite the bullet and install a cooler. After thousands of "flatlander" towing miles without issue, we recently pulled the camper up a ~2-mile dirt incline and the trans temp hit 245. Too hot! This is frustrating, given the truck is rated to tow way more than our 5.0 and has <25K miles. We never have an issue when towing flat and moving, only when going uphill slowly or maneuvering the trailer.

I've learned a little more that others might find useful. The 2014-2018 Silverado (and I assume GMC) have a cooler "integral" to the AC condensor and there is no Chevy option to add more cooling capacity.



The factory cooler has a thermostat (thermal bypass valve) that bypasses the cooler until the fluid hits ~192. Why they want it to heat that high is a mystery for me.

Searching online, I discovered GM issued a service bulletin (link to 21-NA-199) to address multiple transmission complaints. The bulletin prescribes replacing the bypass valve with a newer version. The replacement opens at 154 degrees - a BIG difference in philosophy.

I now plan to replace the bypass valve AND add the Mishimoto cooler. Hopefully the two will correct the issue.

[CharlesinGA]

Other brands of coolers are https://www.haydenauto.com/en/market...ission-coolers
who probably invented the cooler used by Fred Flintstone.........

https://derale.com/ who makes a line of transmission coolers.

or look at a site like https://www.summitracing.com/search/...oling-products for the Derale products and if you search, many others.

You might find that a deep aluminum pan will do a very good job at dissipating heat also. Also be sure and whenever possible, limit the transmission to whatever gear is direct drive (1 to 1 ratio) if it has direct drive. The engine will spin faster than in the over drive gear(s) but the transmission will run much cooler. Depending on what you are towing, you don't want the transmission hunting for gears and its best to limit it so it doesn't upshift only to find that it cannot maintain it and then downshift again.

My Sprinter chassis motor home had a 5 speed automatic. If I limited it to 4th right off, the temp would take 60 miles or more to even get to 130 or so. If I shifted to 5th it would go right up to 170 or more as the gears were then carrying loads.

Some new transmissions do not have a direct drive and use one or more combinations of gear sets to achieve ratios.

Charles

[salmo7000]

I have a 2017 Chevy Colorado that tows my 19. Rather than install a transmission cooler, I’ve just had the dealer change the fluid every 45,000 miles or so, which means I’ve done it twice now. The transmission has gotten a bit hot towing up grades in the summer, but the hottest I’ve ever seen it get was 236. It does exceed 220 more often though. Both times I had it changed, the technician said it was “getting there”, but wasn’t too bad. He said the synthetic fluid they use can take higher temps so there was no need to change it more frequently.

I’m no mechanic, but this seems to me to be a reasonable strategy. The owners manual suggests changing the fluid at 45,000 miles if the vehicle is used to tow a lot. So that’s what I’ve done. The transmission is sealed from being able to check it, but not changing it. I’m assuming your Chevy is the same.

Hope this helps!

[Shiny]

CharlesinGA - thanks for all the info... I did look at other brands but decided to go with the Mishimoto based on dealer recommendations and ease of installation.
I also am aware of the deeper pans with cooling tubes/fins. I will try the cooler first but thanks for bringing that up. As to driving mode, I use the "Tow Mode" to limit hunting but the only time we overheat is in 1st or 2nd climbing a hill under 15 mph. The trans is typically between 180 and 190 on the highway or in town.

salmo7000 - thank you for sharing your experience. I have also read the fluid is quite stable up to about 250 so probably not a crisis but I don't like it running hotter than intended and the cost of trying to reduce the temperature is way less than a new transmission. The service bulletin reinforced my anxiety I guess.

[koakea]

I found this thread in my search for trans coolers. I have the same truck as you, 2018 Silverado LE . 5.3 gas , 6 speed trans. I live in Hawaii and my plan is to order and pickup a 5.0 in spring 2026.

That gives me a few years to get the truck ready. I plan to do three mods, trailer mirrors, pin for the Andersen hitch, and trans cooler. Maybe air bags, not sure if I would need them.

I was wondering if you installed the trans cooler, which one you ended up getting and how its working. Can you give any suggestions on modifications I should make before I pick up the trailer. Thanks

[Shiny]

koakea - thanks for the prod and I like your plan!

We did have the dealer follow the service bulletin and install the reduced-temperature bypass valve along with a Mishimoto cooler.

Unfortunately, the trailer sat all summer as we decided to sell our house and were busy selling and packing.

We made one trip over Monarch pass and so far, the highest temperature I've seen is ~185, which has typically been over 210 so I'm optimistic. We are going camping Friday and will tow up I-70 west-bound grade. I'll update when we return.

The temperatures were highest when there was no airflow - crawling up a steep grade or maneuvering in the driveway. There's no question the cooler and bypass valve have reduced temperatures, I just haven't tested it much towing the camper.

As to other experiences with the truck/5.0 combo, I chose to install a "rail-mount" system for the Anderson hitch. The rails are a nuisance but I don't know that I'd choose differently. We have enough room in the truck bed to hold a lot of stuff so I like the small Anderson "pyramid". A "ball-mount" system in the truck is less intrusive but uses a different Anderson hitch that I believe takes up more bed space.

I have struggled, like others, to keep power to the back-up camera stable. I don't know if this is unique to the truck, but I installed a connector inside the bed (extended from the rear bumper) and added a diode/capacitor widget in the power line. These helped a lot but the power still drops occasionally for no reason. If Escape and/or Furion haven't addressed this, you might consider having Escape wire the camera differently. Read up on this in the forum.

The other "best things" I've learned from the forum have been:

- putting a pool noodle on the hitch ball as a visual guide. This helps a lot!

- adding a shunt-based battery monitor that measures true Amp-Hour usage. This was a huge improvement over the voltage-based "guesses" that came with the camper.

We have been happy with our 5.0 and hope to get some more use out of it.

Mike*

[koakea]

Mike, Thank you for such a prompt reply. I'm excited to hear how your truck does on your next trip. My son lives just off I-70, in St. Peters, MO, about 40 miles west St. Louis. I think that's where I'll be storing the truck and trailer when we get this plan going.

When you mentioned the back-up camera, are you talking about the camera on the trailer? I'll search for the tread you mentioned and read up on it.

Do you have a cover on your bed? If yes, can you close it with the Andersen hitch in the bed? Sorry for all the questions. I appreciate anything insights you may have.

Aloha, Mike

[UncleTim]

A description of the I-70 corridor leading up to Eisenhower Tunnel.

The distance is about 26 miles. The grade is severe at times. Idaho Springs elevation is 7,526 feet above sea level. Eisenhower Tunnel is 11,000 feet with a severe increase in grade immediately after Georgetown culminating at the tunnel itself. Remember motors lose horsepower with elevation and 11,000 is very high.

This run is considered one of the benchmark runs for engine performance and tow-ability anywhere. I too have a transmission cooler in my Tundra. I highly recommend them for high stress, high temperature conditions when you are putting abuse on the engine.