2024 Tacoma Transmission Overheating on Long Climbs Off-Road

[Someguysomewhere26]

In other words the transmission is constantly trying to shift to make the rpm’s as low as possible to conserve gas in my experience going up hill it couldn’t make its mind up to quite literally save its own life.

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[Someguysomewhere26]

One more thing to add sorry for the triple post.

I havnt gone off-roading since I had my transmission REPLACED and I will say that this one responds to pretty much everything very differently then the last one did.

Coincidence maybe

 

[joebangle]

One more thing to add sorry for the triple post.

I havnt gone off-roading since I had my transmission REPLACED and I will say that this one responds to pretty much everything very differently then the last one did.

Coincidence maybe

What kind of issues were you experiencing when they decided to replace the transmission? Overheating, weird shifting, warning codes, leaking fluid, total failure?

 

[Someguysomewhere26]

No codes no warnings other then a hard first shift after a cold start

Long story short it was slamming into gears hard while driving 7k miles

I did have the overheating on climbs and off-road ect but that’s extremely common

The official paperwork said high pressure in transmission they didn’t tear it apart and investigate after that just replaced it.

It wasn’t related to the tsb however it was replaced hassle free

I have a thread I gotta figure out how to link it here.

 

[Will721]

In other words the transmission is constantly trying to shift to make the rpm’s as low as possible to conserve gas in my experience going up hill it couldn’t make its mind up to quite literally save its own life.

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.

 

[Someguysomewhere26]

I lean towards this as well since in my personal experience, putting it into sequential and telling it what to do it runs perfectly fine

However, if you let it make the decisions it struggles

Tells me it’s more software related then hardware related so I cope and hope it’s still mechanically built well but programmed bad.

Time will tell

Either way very upsetting and if it was designed this way I wish they would come out and say something

Something as simple as to maintain regulations we had to do xyz to prevent issues do xyz and this would be a non issue we would all get it and move on.

Bit late for that tho and with the amount of complaints with no response makes me nervous.

 

[GSPHerder]

I wonder if the tuners address or affect the tranny/shifting issues??

 

[MT-Taco]

I’ve probably got 12-16k miles off road slow crawling to blasting around, mines never overheated, it’s been warmer than usual at times but hasn’t been a problem for me. If anything Its impressive how well it tackles off-road obstacles. TFL crew got their TH test rig hot (not over heated) but they were towing on a slow and steep climb.

The transmission cooled/heater is on the warm side of the radiator, for me is a good thing when temps reach —40f. Yet still seems fine at 100f.
If a guy/gal wanted you could easily add longer hoses and move the trans cooler to the cold side of the radiator?

 

[GSPHerder]

I’ve probably got 12-16k miles off road slow crawling to blasting around, mines never overheated, it’s been warmer than usual at times but hasn’t been a problem for me. If anything Its impressive how well it tackles off-road obstacles. TFL crew got their TH test rig hot (not over heated) but they were towing on a slow and steep climb.

What size tires you running, the actual diameter? I just swapped my mud terrains for some taller 34.8" AT's, I noticed right away the tranny isn't as decisive and seems to have lost lots of responsiveness. That upgrade in tire size definitely affected shift points.

 

[Someguysomewhere26]

I’m curious to see how mine acts now it’s been replaced.

It shifts better no more cold start hard shifts ect

Also it’s common for these transmissions to be under filled from factory which isn’t helping

 

[Lando]

@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.

 

[Dutchman4]

The transmission does tend to up shift rather quickly when accelerating from a stop, probably to keep the RPM's low for better fuel economy.
The other think I noticed is that when you apply a little more throttle, at most any speed, the transmission is very reluctant to down shift and instead it stays in the current gear and just relies on the engine to apply more boost instead. This low RPM "lugging" effect on the engine bothered me, especially early on in the break-in period, to the point where I enabled the ECT-POWER mode button for the remainder of the break-in period. The ECT-POWER mode is similar to TOW-HAUL mode in that it doesn't down shift but instead it holds the current gear longer before up-shifting.
If you google Tacoma 4th gen ECT mode it will say that it has been discontinued for the 4th gen but it is present on my SR5-4WD ExtraCab.

 

[Bcphoto3]

I should have made it clear that my "use case" for the 2010 Tundra was for an OFF-ROAD situation where the road was so rough that I was forced to drive slow.

If your 4th gen Tacoma has transmission overheat problems per your above statement:
"What I don't understand is the overheating will occur when in 2wd driving slowly up a paved mountain road." then your local dealer service departement needs to resolve this because there is something wrong.

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..

 

[MT-Taco]

What size tires you running, the actual diameter? I just swapped my mud terrains for some taller 34.8" AT's, I noticed right away the tranny isn't as decisive and seems to have lost lots of responsiveness. That upgrade in tire size definitely affected shift points.

Nokian 285/70r17 32.8”

 

[Will721]

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.

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