2024 Tacoma Transmission Overheating on Long Climbs Off-Road

[Bcphoto3]

Yeah, they used to be. I agree, this is unacceptable and I don't think Toyota cares.

I agree that this is unacceptable. And it seems that Toyota doesn’t really care about improvement/ complaints from its customers. Fuel tank size, gas mileage on hybrids, 12v battery problems, transmission over heating! My dealer has expressed using a trickle charger, getting a trans cooler. All of these things should have been figured out by competent engineers before release of vehicle.

You have to ask yourself why people buy toyota products. They do not have more horse power, not more luxurious inside, not as electronically/ tech advanced, doesn't have more space, and certainly not a bargain compared to the competition.
The only things they have going for them is longevity, durability and resale value. Take away longevity or durability and the value and main reason to buy one disappears. I'm not sure what the business model is at this point. Apparently they adopt passenger car engines and transmissions to their trucks and suv's with minor modifications and for some reason don't provide extensive testing before launching the updated models? Oh and not to mention the 8spd transmissions had all sorts if issues in the sedans that were sold? Toyota knew these transmissionshad issues from the get go.
If I didn't know any better, toyota is expecting their customers to buy $50k vehicles AND do the preliminary beta testing on them. I don't see how this contributes to their legacy, and certainly doesn't build confidence from the consumer. I'm frankly amazed at how Sheldon Brown dropped the tacoma program like a hot potato once they were transfered to another project. The lead engineer hyped up the product, and left the customers holding the bag. Do better Toyota!

I like my Tril Hunter but am considering going to Ford or Chevy for next truck.. My 2008 4 Runner was great and actually still running well with 320Kmiles with almost no trips for service other than regular maintenance for the first 200K miles. I expected similar experience with this Tacoma, but after 18 months of ownership, I am very disappointed.. I am modifying items that are wrong. ( getting LRA tank put on lter this year, will get Trans cooler at same time since have been in limp mode several times). Starting to look at Chevy and Ford models and will decide when to pull trigger on switch..

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[Kodachrome]

So here is my .02, as a long time Toyota owner.

My 07 Fj has always done this. It doesnt have a trans temp gauge. That thing has been loaded down for 16 years now, and I have driven all over the place. In early ownership, I owned it and never paid any attention or even thought about it. Once I installed the Ultragauge 6-7 years of ownership I was shocked by how hot my transmission was getting. 230+. What I learned was that even in 4L it would get hot if it was in D. If for instance I am in 4L, D, and I know for a fact its in 2nd gear and it starts getting hot, I can shift to 2nd gear in "manual mode" and it cools down immediately. I am assuming there is just more slippage and pressure buildup with the transmission anticipating a shift if you are in D, but in manual mode you lose that addtional heat.

When my Trailhunter still had the factory bed, but 35" tires and a bed rack/tent and towing a ~3k trailer, I saw temps climb while going up Aspen mountain which is a pretty steep climb, and takes roughly 20-30 minutes to summit. The truck was still pretty new to me, and I was learning the ins and outs. I saw it starting to heat up once on that trip, but only during that initial climb which was at night, but in October. I for sure was in 4L, but I believe I was just in D. I let it cool down for like 2 minutes tops and it was ready to go.

Flash forward and my truck is fully built and is certainly one of the heaviest out there. I did Redcone pass which is also a really steep climb for a good hour or two, and while I saw my temps start to rise, I am pretty aware of it and usually shift into manual mode and it cools itself off pretty quick. I did see it getting extra hot on a long section but I had to stop and wait for a friend anyway, so it naturally cooled down pretty quick.

I should add to this, Vail pass, steep highway stuff, no issues at all.

If you are going under 20mph off road, shift to 4 low. If its extra steep and starts to warm up, manually shift down. And don't wait until you get a warning to do so. I am willing to bet this will solve most of the issues people are having. Perhaps some summer desert driving will change my mind on this, but I have done some of that already and didnt have issues.
Its designed this way. And if you must haul ass up steep stuff in 2 or 4h, still try manually shifting, and get the RPMs to around 3k or better and you will be surprised how much better it does.

Excuse my dramatic thumbnails. Its the nature of the YT beast

I have had my 2026 Trailhunter long bed for about three weeks, been driving it a lot to break it in properly which has been great, at 1450 miles now.

Let's set the stage, I live about 20 miles from Aspen, do the back and front side of Aspen Mountain several times a year. I also do lots of passes like Independence, McClure, etc when getting to the other places I off-road and camp. I have not owned a naturally aspirated car since 2008, supercharged my 2005 Tacoma then and have had turbo Audi cars since then including a stage-2 Audi RS7. Forced induction motors do not like lugging, especially turbos.

After I changed my oil out at 600 miles in the new ride, I did the backside of Ajax via Little Annie basin road, still about 2800' vertical over I think 4 miles. I had it in 4Hi for the first mile, in manual with rpms around 2500-3200. Then once past the houses and just before the first steep grade, put it in 4Lo and again, kept it manually set, rpms now 3000-4000. Once I got into sections of little to no rocks but still good grades, I put it in S mode in 4Lo and blasted it into the mid rpm ranges, sometimes as high as 4500.

When I got to the top of Aspen Mountain, my iDash Pro gauge showed 228F.

Fast forward to yesterday. I drove over Independence Pass to meet a guy to sell my bed bar, the drive was at 7AM, nice to avoid the oncoming traffic in the narrows. I mixed it up a lot, D, S, M all according to keeping a nice healthy RPM/ engine load, max temp at the pass was 222F, got a nice 24.2mpg to BV. I then decided to make a nice loop out of it and see a friend in Paonia. I went down to Poncha Springs, caught 50 West so up and over Monarch Pass. I had no traffic and had fun in M moving between 4th, 5th and 6th, 2800-4200rpms, really trying to burn those rings in well now at 1200 miles in. The temp at the top of the pass in this spirted run was 226F.

Hung out with my friend in Paonia for a few hours and then off to run it up McClure pass. As you probably know, the last 6 miles to the top is a really fun uphill, lots of places to really rail it and a few turns mixed in. I ran it in manual in 4th and 5th gear and 3300-4300 rpms, just screamed beautifully up the grade and had plenty of pedal left, boost was held at around 7-10psi. In the last mile it hit 230F but not over.

I have yet to do a D mode torture test on it because the lower rpms in a higher gear and heavy load readout just make no sense to subject a 4 cylinder turbo engine to, even if hybrid. This truck is not hard to switch into 4Lo and it happens reliably so I will just make that move when it makes sense which is more often then previous wisdom might otherwise dictate.

All this being said, I really want to see even 230F go away, so I will consider the aux trans cooler, especially considering I am going to be putting my 4Wheel pop-up camper on it at some point. My only hesitation is warm up during Winter because unlike my Audi, the truck lives outside.

 

[lauren01]

I have had my 2026 Trailhunter long bed for about three weeks, been driving it a lot to break it in properly which has been great, at 1450 miles now.

Let's set the stage, I live about 20 miles from Aspen, do the back and front side of Aspen Mountain several times a year. I also do lots of passes like Independence, McClure, etc when getting to the other places I off-road and camp. I have not owned a naturally aspirated car since 2008, supercharged my 2005 Tacoma then and have had turbo Audi cars since then including a stage-2 Audi RS7. Forced induction motors do not like lugging, especially turbos.

After I changed my oil out at 600 miles in the new ride, I did the backside of Ajax via Little Annie basin road, still about 2800' vertical over I think 4 miles. I had it in 4Hi for the first couple miles, in manual with rpms around 2500-3000. Then once past the houses and just before the first steep grade, put it in 4Lo and again, kept it manually set, rpms now 3000-4000. Once I got into sections of little to no rocks but still good grades, I put it in S mode in 4Lo and blasted it into the mid rpm ranges, sometimes as high as 4500.

When I got to the top of Aspen Mountain, my iDash Pro gauge showed 228F.

Fast forward to yesterday. I drove over Independence Pass to meet a guy to sell my bed bar, the drive was at 7AM, nice to avoid the oncoming traffic in the narrows. I mixed it up a lot, D, S, M all according to keeping a nice healthy RPM/ engine load, max temp at the pass was 222F, got a nice 24.2mpg to BV. I then decided to make a nice loop out of it and see a friend in Paonia. I went down to Poncha Springs, caught 50 West so up and over Monarch Pass. I had no traffic and had fun in M moving between 4th, 5th and 6th, 2800-4200rpms, really trying to burn those rings in well now at 1200 miles in. The temp at the top of the pass in this spirted run was 226F.

Hung out with my friend in Paonia for a few hours and then off to run it up McClure pass. As you probably know, the last 6 miles to the top is a really fun uphill, lots of places to really rail it and a few turns mixed in. I ran it in manual in 4th and 5th gear and 3300-4300 rpms, just screamed beautifully up the grade and had plenty of pedal left, boost was held at around 7-10psi. In the last mile it hit 230F but not over.

I have yet to do a D mode torture test on it because the lower rpms in a higher gear and heavy load readout just make no sense to subject a 4 cylinder turbo engine to, even if hybrid. This truck is not hard to switch into 4Lo and it happens reliably so I will just make that move when it makes sense which is more often then previous wisdom might otherwise dictate.

All this being said, I really want to see even 230F go away, so I will consider the aux trans cooler. My only hesitation is warm up during Winter because unlike my Audi, the truck lives outside.

Sounds like you really know your shit, friend. Please do yourself a favor and fully bed in your piston rings before you do the pushing. Every engine deserves a gentle break-in to progressively more challenging.

I share some of the sentiments addressed in the string above. My example has been the vehicles that my father bought for our family to tow our 19 foot boat and later a 26 foot boat. We bought American. And we were always fixing those giant pieces of fucking shit. My father took meticulous care and spent hard-earned money on good mechanics with references from his friends who knew more than he did. He always took me along, so I absorbed quite a bit since the 1970s through the early 2000s when he stopped buying trucks because he got too old to go fishing anymore. I have had Nissan, Datsun, Mazda, Honda & Acura, and this is my first Toyota. I took after my dad and probably went a step further with obsessing over basic maintenance and quality of supplies. I found that my dad had gotten punished for buying American, so I have not bought American brands. Also, Dad told me not to. LOL. I have a few cousins my age that have always bought American and have nothing but transmission replacements, blown pistons, threw a rod, leaky engines, and this is not even at 70,000 miles. And these fuckers insist they take meticulous care of their cars. I am ranting because I am angry at the whole car industry right now. I can’t even trust Toyota either. I have had problems with my Toyota throwing a hybrid battery system malfunction code because the Trailhunter got some water in it? And Toyota hasn’t even offered a solution or acknowledged formally what the problem is, even though the techs have whispered it in my ear. They fucked this thing up. However, I know how to fix it now. And there are workarounds. One of my solutions has to been to get Starlink mini. We needed new Internet anyway in the house, and it was really hardly anything extra to get mini in our area. So at least I can call for help if we are hunting for Bigfoot and the truck goes haywire. But guess what, the Chevy, Ram, or Ford would crap out on the highway on the way there. Giant pieces of shit that I will never own. Everyone of my friends who has had one has had nothing but GRIEF.

I don’t cuss on here much, so I hope that you can forgive me if you hate seeing cussing. But I feel that strongly about American vehicles. I am very sad about those, including Tesla, which I did not get for a daily driver because it is another giant piece of shit. All my friends who have them, including three of my neighbors, have nothing but problems. Everybody needs to stop beta testing on our time and hard-earned money.

All that bullshit said, thank you for reading, I still love my truck.
/rant over!!!!

 

[Kodachrome]

Sounds like you really know your shit, friend. Please do yourself a favor and fully bed in your piston rings before you do the pushing. Every engine deserves a gentle break-in to progressively more challenging.

I share some of the sentiments addressed in the string above. My example has been the vehicles that my father bought for our family to tow our 19 foot boat and later a 26 foot boat. We bought American. And we were always fixing those giant pieces of fucking shit. My father took meticulous care and spent hard-earned money on good mechanics with references from his friends who knew more than he did. He always took me along, so I absorbed quite a bit since the 1970s through the early 2000s when he stopped buying trucks because he got too old to go fishing anymore. I have had Nissan, Datsun, Honda & Acura, and this is my first Toyota. I took after my dad and probably went a step further with obsessing over basic maintenance and quality of supplies. I found that my dad had gotten punished for buying American, so I have not bought American brands. Also, Dad told me not to. LOL. I have a few cousins my age that have always bought American and have nothing but transmission replacements, blown pistons, threw a rod, leaky engines, and this is not even at 70,000 miles. And these fuckers insist they take meticulous care of their cars. I am ranting because I am angry at the whole car industry right now. I can’t even trust Toyota either. I have had problems with my Toyota throwing a hybrid battery system malfunction code because the Trailhunter got some water in it? And Toyota hasn’t even offered a solution or acknowledged formally what the problem is, even though the text have whispered it in my ear. They fucked this thing up. However, I know how to fix it now. And there are workarounds. One of my solutions has to been to get Starlink mini. We needed new Internet anyway in the house, and it was really hardly anything extra to get mini in our area. So at least I can call for help if we are hunting for Bigfoot and the truck goes haywire. But guess what, the Chevy, Ram, or Ford would crap out on the highway on the way there. Giant pieces of shit that I will never own. Everyone of my friends who has had one has had nothing but GRIEF.

I don’t cuss on here much, so I hope that you can forgive me if you hate seeing cussing. But I feel that strongly about American vehicles. I am very sad about those, including Tesla, which I did not get for a daily driver because it is another giant piece of shit. All my friends who have them, including three of my neighbors, have nothing but problems. Everybody needs to stop beta testing on our time and hard-earned money.

All that bullshit said, thank you for reading, I still love my truck.
/rant over!!!!

Not a problem, I get it. I have driven Toyotas in truck form since my first, a used 2WD 1982 5 speed. I have also driven a Subaru, VW and Audi. I am going to knock on wood and say none of them have left me stranded due to bad engineering or a widespread defect. Any issue I have had with a car has been due to me, either going too hard on a tune, off road blowing up suspension parts, warping rotors by just flat out devouring a fine Colorado twisty or just a wear item.

I took it pretty easy on the new truck the first 500 miles, then gradually started going into higher rpm ranges beyond that but very little high load situations. Once past 1,000 miles, I upped the load a fair bit with high boost sprints for a couple seconds. 3000-4000 rpms on any 4 cylinder that reds at 6K or more is a pretty safe area to run the engine at, even if max tq is developed down low and by my experience, that includes break-in past 300 miles or so, especially if you have swapped out the factory oil before giving it more go.

So you are right, you have to bed the rings in well and in my case, the last 2 miles of my commute home is up and down a 800' foot gain / loss over that distance, so no avoiding certain engine parameters. You have to be gentle for sure, but you also have to gradually up the load scenarios and use more and more of the rpm range in the first few thousand miles to correctly set the stage for longevity.

Only time (and an oil analysis) will tell how well I did with that.

 

[joebangle]

I completely understand using the different selections on the transmission, but when driving on paved roads driving up mt. Washington 4 low will cause excessive binding and bucking when traveling on the paved switch backs. I haven't found an option to put the truck in 2 low like the old trucks where you simply didn't engage the front axle hubs. I would presume a truck would be overdesigned with extra safety margin to drive up a mountain road. Especially not towing, not heavy and with factory oe tires etc. If you are unable to drive traveling at 10-15mph up a paved incline without transmission overheating, the testing or engineering was not fully vetted. I could understand if the truck was towing heavy loads, or fully laden with weight but this wasn't the case. It's as though there wasn't any safety margin for a light truck traveling up a slow winding paved steep road. The other aspect that is concerning is the unfortunate known issues with the 8spd transmissions in other passenger car models. Toyota in their infinite wisdom decided to adapt a problem child transmission to rear wheel or 4 wheel drive and expected a seemless outcome. It's almost as though toyota took the cheapest parts bin engineering approach to the new tacoma model to save money. Turbo passenger car engine slightly modified for truck use, passenger car transmission modified for a truck application. Apparently toyota expects these "trucks" to be used lightly and without a safety margin necessary for actual work. Sheldon Brown Apparently focused on low having fruit instead of developing a more durable and capable tacoma for the north American market. And u.s. consumers took the bait hook line and sinker...

 

[lauren01]

Not a problem, I get it. I have driven Toyotas in truck form since my first, a used 2WD 1982 5 speed. I have also driven a Subaru, VW and Audi. I am going to knock on wood and say none of them have left me stranded due to bad engineering or a widespread defect. Any issue I have had with a car has been due to me, either going too hard on a tune, off road blowing up suspension parts, warping rotors by just flat out devouring a fine Colorado twisty or just a wear item.

I took it pretty easy on the new truck the first 500 miles, then gradually started going into higher rpm ranges beyond that but very little high load situations. Once past 1,000 miles, I upped the load a fair bit with high boost sprints for a couple seconds. 3000-4000 rpms on any 4 cylinder that reds at 6K or more is a pretty safe area to run the engine at, even if max tq is developed down low and by my experience, that includes break-in past 300 miles or so, especially if you have swapped out the factory oil before giving it more go.

So you are right, you have to bed the rings in well and in my case, the last 2 miles of my commute home is up and down a 800' foot gain / loss over that distance, so no avoiding certain engine parameters. You have to be gentle for sure, but you also have to gradually up the load scenarios and use more and more of the rpm range in the first few thousand miles to correctly set the stage for longevity.

Only time (and an oil analysis) will tell how well I did with that.

Hallelujah, that’s what I have done as well. I I have been having my oil analyzed and I’m going to send in a third one at the next oil change. In between the the second and third change, I started smelling fuel in the oil because I had not taken as many long trips. I took it to Toyota at 9000+ miles, and got my first Toyota freebie oil change after the first two on my nickel. Vehicles anre only kids once, and you gotta raise them right.

Had a bath and a beer after a failed attempt at installing a new Optima Yellowtop. Can you tell I was madder than a wet hen today, when after we had the OEM battery out of the truck for an hour, then had to put it back in, ignition would not turn over and we had to jumpstart. Now we have it on a maintainer overnight. More on that later once the problem is solved.

We upgraded the wife’s ‘24 Subaru Outback with an Interstate AGM battery from Costco, first thing this morning, with good fitment. 50/50 “car mod” success today.

 

[GSPHerder]

175–200°F (79–93°C)ElevatedCommon during towing or hillsATF begins mild oxidationMonitor temp if towing; consider external cooler
200–220°F (93–104°C)HotHigher-than-ideal tempATF breakdown acceleratesReduce load; stop to cool if needed
220–240°F (104–116°C)Very HotATF is losing viscosityTransmission wear increases rapidlyStop driving; allow cooling
240–260°F (116–127°C)OverheatingDamaging rangeClutch plates glaze; seals hardenService may be required soon

Ive seen these numbers on alot of different sites. So much for" lifetime/sealed" trannies when at 220degrees your eating into the life of the fluid.

 

[Kodachrome]

175–200°F (79–93°C)ElevatedCommon during towing or hillsATF begins mild oxidationMonitor temp if towing; consider external cooler
200–220°F (93–104°C)HotHigher-than-ideal tempATF breakdown acceleratesReduce load; stop to cool if needed
220–240°F (104–116°C)Very HotATF is losing viscosityTransmission wear increases rapidlyStop driving; allow cooling
240–260°F (116–127°C)OverheatingDamaging rangeClutch plates glaze; seals hardenService may be required soon

Ive seen these numbers on alot of different sites. So much for" lifetime/sealed" trannies when at 220degrees your eating into the life of the fluid.

These are about 20F degree cooler temps for the same effects as I have been finding online. Either way I am not "cool" with 220-230 as I am seeing so I will look into an aux cooler. I also need to add the Toyota gauge to one of my readouts so I can at least compare what the scale is saying vs my actual temps on the iDash gauge.

 

[joebangle]

These are about 20F degree cooler temps for the same effects as I have been finding online. Either way I am not "cool" with 220-230 as I am seeing so I will look into an aux cooler. I also need to add the Toyota gauge to one of my readouts so I can at least compare what the scale is saying vs my actual temps on the iDash gauge.

I have no idea what the transmission temperature was, but it was almost all the way to the red. And this was stopping several times with engine running in the ascent. We drove up a smaller mountain area called Miller state Park same scenario but smaller mt. Packmanadnock. Paved road switch backs, not as steep and transmission still managed to be slightly higher than half way point. I had to put the truck in park at the top and Rev the engine for maybe 10 minutes at 2k rpm to bring the temps back to the middle normal halfway point. Frankly this is a huge pia simply driving up a small mountain and doing all of these preventative measures because Toyota didn't get their platforms up to speed. Toyota royaly screwed up with the transmission design or cooling on these Tacomas...

 

[lauren01]

I have no idea what the transmission temperature was, but it was almost all the way to the red. And this was stopping several times with engine running in the ascent. We drove up a smaller mountain area called Miller state Park same scenario but smaller mt. Packmanadnock. Paved road switch backs, not as steep and transmission still managed to be slightly higher than half way point. I had to put the truck in park at the top and Rev the engine for maybe 10 minutes at 2k rpm to bring the temps back to the middle normal halfway point. Frankly this is a huge pia simply driving up a small mountain and doing all of these preventative measures because Toyota didn't get their platforms up to speed. Toyota royaly screwed up with the transmission design or cooling on these Tacomas...

I think they should foot the bill to change our fluid for us. I have gotten mine nearly 3/4 of the way to hot… need to do a drain and fill before the next big trip coming up soon.

 

[joebangle]

I think they should foot the bill to change our fluid for us. I have gotten mine nearly 3/4 of the way to hot… need to do a drain and fill before the next big trip coming up soon.

I honestly think the not only need to service these transmissions, but also update the shifting and torque converter lockup programing. Possibly add a larger liquid to liquid transmission cooler as well. These offroad models are supposed to cater to adventure mInded drivers doing exactly what we are using them for like driving up mountains. From my perspective if the transmission overheats simply driving up a mountain, then it wasn't designed properly. I didn't see anyone else with their minivans or sedans having to Rev their engines or wait at idle for any length of time to get their transmission temps down. And the best part is explaining to your impatient kid that they can't get out and explore because we have to cool the transmission off for 10 minutes. This is completely absurd to have to do this when every other vehicle including Honda civics and Subaru wagons don't have issues. Sorry for the rant but it's obviously frustrating...

 

[Lando]

A couple weeks ago I crossed the Canadian Rockies and back on Hwy 5 and Hwy 1. Drove through Roger’s Pass in 28C - 30c+ (82F - 90F) temperatures. Steady climbs for an hour. No issues, kept an eye on the trans gage because of this thread and saw it peak at just past the halfway mark, never higher. Truck performed as expected on the entire 3200km (2000 mile) round trip. No off roading so always in 2Hi.

I wonder if it’s some trucks and not across the board? Either way I agree with you all this is bs. A dedicated transmission cooler on at least the off road trims should have been a given!

This may not be a popular place to read this here, especially with @lauren01 but I still standby the best trucks I ever owned were my GMT400 K1500’s - Silverado & Yukon. Both had over 200k miles on them (Yukon had 250k miles - 400k km). Both original engines and transmissions. Pretty well only regular maintenance and a transfer case in one. Logging roads, up mountains, in winter and summer. Never in 4Lo except once I remember. Never an overheating problem of any type. Only fault really would be the mileage. (Tacoma is definitely better mpg, as I’d expect as it is smaller too). Maintenance was easy to do, even at home. Parts were low cost.
I wanted a Tacoma for a long time and really like mine so far, but gotta say it’s not on the pedestal I thought it was anymore. And threads like these, people shifting to 4Lo just to avoid transmission overheating, are unsettling and doing that is unheard off in my old Chevs and GMs.
I will say for new trucks, a Tacoma is still the only one I’d buy (unless you need a HD or towing capacity). GMs are not the same and don’t seem to be as durable as the GMT400’s were.

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