2024 Tacoma Transmission Overheating on Long Climbs Off-Road

[TacoFreak]

Except the dealers arent.. They response is “you need a transmission cooler”. No fucking shit.. And Toyota should have put one in, just like they should have put in an alternator and a larger gas tank and not lied about MPG..

Yep, just like their answer about my truck not keeping the 12 volt battery charged. Their response was "you need a trickle charger". I didn't even explain to the idiot why that was stupid, and why what you really need is a battery maintainer. My lifetime combined average fuel economy is 7 mpg below the rated mileage, and I don't flog my truck or drive much above 75 mph.

The dealers aren't doing anything to fix these problems, it is all on us. If I wouldn't lose so much money and didn't love my truck so much I would be pissed off enough to move on.

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[Someguysomewhere26]

Oh come on they are only 40-70 thousand dollar trucks don’t be so harsh

 

[joebangle]

@joebangle agree with your posts. Some of the solutions to not overheat the transmissions seem like we’re going backwards to me, as old trucks were tougher and did not need these solutions. I will say I’ve had no issue with my 2024, though it has not been off road much on mountains, it has been through the hwys in the Canadian Rockies.

Going uphill in 2wd on pavement I never had a transmission overheat issue in my GMT400 Chevys! And off road on abandoned mountain logging roads I was never in 4Lo. I was taught 4Lo was for the 10% of the time you get really stuck. 90% of my off-roading was in 4Hi.

I completely agree. 4low is supposed to be designed for out of the ordinary situations, not routine dirt trails etc. I have always looked at it as a last resort things have gone sideways situations. A truck should never spike its transmission fluid temps in 2wd. Even towing within its rating you should never see a spike. Simply driving up a paved incline or mountain should be an easy task for a pickup. If not, something wasn't designed correctly. Like I mentioned earlier, these trucks should be designed to tackle any paved road in north america in drive without seeing a transmission temperatures spike. If not it simply was not designed for being used in North America...

 

[joebangle]

This is most likely the actual reason for the issue. While it is a design flaw, its probably intentional. Gotta keep the EPA happy. They don't care if your car lasts 500 miles, so long as it doesn't burn any fuel and filters the hell out of the exhaust while doing it.

I'm not sure it's completely an epa issue. I don't think the epa tests these vehicles in normal and power modes, it's likely only in the eco setting. And you could change shifting protocols when used in the eco mode to get the best fuel economy. Personally I think they did just enought to get the vehicle to market and fix whatever is revealed at a later date. This reduces r&d time, and makes following changes voluntary for the manufacturer...

 

[joebangle]

A note on old trucks, most had an auxiliary transmission cooler from the factory. Especially on anything with a towing package. However, they did not have a thermostat for the transmission cooling system. That is a more recent addition.

Why do they have a thermostat for the transmission now? Because they need it to heat up faster. The sooner the transmission is up to temp, the better. A cold transmission is not as efficient, and has more conservative shift points to protect it. Hot fluid has less parasitic drag, and shift points on electronically controlled transmissions change once up to temp.

Efficiency is everything and manufacturers are slaves to those regulations. Its why we went to direct injection, low displacement with turbos, 8 speed+ transmissions, cvts on cars, auto start stop, hybrids in nearly every model, low profile tires, all of it. Chasing imaginary numbers determined by a bunch of people uneducated on the subject while the rest of the first world countries take a completely different approach. Not even including the underdeveloped nations.

Most older vehicles had an indirect thermostat. The transmission lines were part of the radiator and whatever controlled coolant temp of the engine indirectly correlated to the transmission temp. I think the loop went to an air to air transmission exchanger then back to the lower radiator tank to maintain a constant operating temperature. The specialized transmission only thermostat is a fairly new idea likely to help the transmission warm up faster on cold winter mornings...

 

[Will721]

I'm not sure it's completely an epa issue. I don't think the epa tests these vehicles in normal and power modes, it's likely only in the eco setting. And you could change shifting protocols when used in the eco mode to get the best fuel economy. Personally I think they did just enought to get the vehicle to market and fix whatever is revealed at a later date. This reduces r&d time, and makes following changes voluntary for the manufacturer...

The Epa tests all vehicles via a simulated drive in a closed testing cell on a rolling road similar to a dynamometer. You can look up testing criteria and conditions, but they do test in all drive modes. Manufacturers cannot bypass or go outside of epa parameters with a tune or drive mode of any kind. That's what got Volkswagen in trouble.

Most older vehicles had an indirect thermostat. The transmission lines were part of the radiator and whatever controlled coolant temp of the engine indirectly correlated to the transmission temp. I think the loop went to an air to air transmission exchanger then back to the lower radiator tank to maintain a constant operating temperature. The specialized transmission only thermostat is a fairly new idea likely to help the transmission warm up faster on cold winter mornings...

That is not a thermostat and infact has zero temperature regulation. The coolant in a radiator is not controlled in any way. Yes, it was designed to help heat transmission fluid and cool it but there was no control. The engine thermostat only controls temperature inside the engine itself and any coolant in the radiator can vary wildly based on driving conditions and ambient temperatures. It is entirely possible and common for transmissions cooled in that way to never reach operating temperatures in colder weather.

The whole point of the transmission thermostat is to put as much heat as quickly as possible into the transmission after start up. A side effect is it is a restriction and never let's the fluid drop below its set temp. Which could help overall temperature averages in driving conditions where a large swing would be present. I.e. Trail driving with steep grades and long down hill sections.

 

[LS13]

How does the Limited version with its full time 4WD not burn out its Transmission ?

 

[OminousSkitter]

The Epa tests all vehicles via a simulated drive in a closed testing cell on a rolling road similar to a dynamometer. You can look up testing criteria and conditions, but they do test in all drive modes. Manufacturers cannot bypass or go outside of epa parameters with a tune or drive mode of any kind. That's what got Volkswagen in trouble.

I always heard they tested the default settings when you turn the car on--not change drive modes. That is why no factory ESS implementation remembers whether you turned it on or off; it will always be enabled when you start the car and you must turn it off. I assumed the same would be true with drive modes, that is they don't test sport or eco unless that's the default when you start the car.

 

[redlimitediforcemax]

How does the Limited version with its full time 4WD not burn out its Transmission ?

I haven't experienced any overheating in mine. But the landcruiser guys have and its basically the same

 

[24tacoman]

I wonder if the manual transmission is subject to the same issues. There is no temp gauge but now I would be curious to install one. Maybe these trucks just naturally run hot. I would imagine almost all of the heat in the auto comes from the torque converter slipping in higher gears than it needs to be in for the situation, and 4Hi puts even more drive train resistance which makes the slipping create even more heat... I have also read a bunch of cases (3rd gen had this problem too) where the transmission was severely under filled from the factory.

 

[TacoMagnetic]

I wonder if the manual transmission is subject to the same issues. There is no temp gauge but now I would be curious to install one. Maybe these trucks just naturally run hot. I would imagine almost all of the heat in the auto comes from the torque converter slipping in higher gears than it needs to be in for the situation, and 4Hi puts even more drive train resistance which makes the slipping create even more heat... I have also read a bunch of cases (3rd gen had this problem too) where the transmission was severely under filled from the factory.

If you are looking for a guage that can read the trans temp for the 3rd and 4th gen, Banks iDash has it covered. I have three in my '18 TRD/OF. See the middle gauge. No extra sensor needed; it reads right off the ECU broadcast.

Drop your year, make, and model here to see what iDash will display: https://bankspower.com/pages/banks-idash-pro-what-data-is-available-for-your-vehicle

 

[Elyk Scott]

I wonder if the manual transmission is subject to the same issues. There is no temp gauge but now I would be curious to install one. Maybe these trucks just naturally run hot. I would imagine almost all of the heat in the auto comes from the torque converter slipping in higher gears than it needs to be in for the situation, and 4Hi puts even more drive train resistance which makes the slipping create even more heat... I have also read a bunch of cases (3rd gen had this problem too) where the transmission was severely under filled from the factory.

It would be helpful to run the Banks iDash. The iDash provide a window into your vehicle's engine and transmission by displaying hundreds of pressures, temps, speeds, and more that your dashboard doesn't. You'll be able monitor transmission temps, boost temps, trans gear, and a plethora of other pids. It's a great way to monitor the truck the way it was intended. Manufactures don't think about longevity of vehicles anymore, it's really up to us as consumers to do our due diligence. Banks definitely helps make that part easy.

Banks iDash Pro® Standalone for 2008+ OBDII CAN bus vehicles (66710) - Default Title - Banks Power

 

[GSPHerder]

I like it ^^ but no offense, for that price might as well go with the cobb tuner and a tune. You get the temp gauges but alot more.

 

[TacoMagnetic]

For the 3rd gens, I'm not finding anything with Cobb. For the 4th gen, if monitoring is what you are after and you aren't worried about tuning, $700 versus the $419 for the iDashPro is a bit of a stretch. Plus, there is no warranty risk with the iDashPro.

 

[Elyk Scott]

I like it ^^ but no offense, for that price might as well go with the cobb tuner and a tune. You get the temp gauges but alot more.

None taken, I think it's fair pricing in my opinion. Though, it's not tuning. It's still small sleek and does everything I want. When tuning comes into play, I'll be able to use both in conjunction. Plus, if I ever upgrade or change to a different vehicle, it's not married to the truck. Also, I don't run the risk of my warranty being voided. Pretty solid product.

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