2024 Tacoma Transmission Overheating on Long Climbs Off-Road

[Don Hoe]

2024 OR Premium Hybrid - Anybody else having problems with their transmission overheating specifically on long offroad climbs? And if so, what have you done to fix it? Transmission temperature is normal and shifts normally on mountain highways but the truck overheats on long off-road climbs - anything over about 600m (~2000ft) vertical. I've had warning lights come on twice and now monitor the transmission temperature on climbs and stop for a couple minutes then continue once the transmission cools. I'm not towing or carrying anything more than a couple mountain bikes. These are roads I've done in other trucks and done in tandom with other vehicles and the other trucks including a couple 3G Tacomas and Bronco are not overheating their transmissions. I've tried 4 LOW which shouldnt be necessary on these grades but it doesn't really help. I've asked my dealer about it and was told to install a transmission cooler if I'm going to be doing a lot of offroading. I'll for sure do this but just expected an OR vehicle to not overheat on offroad climbs... Any other solutions people have found?

I have a 2025 trd off road and noticed even when on slippery roads when I shift to 4hi the engine feels like it's under a huge load, shaking and vibrating? Wondering if the gear ratio's between transfer case, front and rear diffs and transmission are slightly off? It's not my first 4X4?

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[TacoFreak]

I have a 2025 trd off road and noticed even when on slippery roads when I shift to 4hi the engine feels like it's under a huge load, shaking and vibrating? Wondering if the gear ratio's between transfer case, front and rear diffs and transmission are slightly off? It's not my first 4X4?

Four bangers are not inherently balanced engines, so under load they are more likely to shake or vibrate. Maybe that is what you are feeling?

 

[Don Hoe]

Four bangers are not inherently balanced engines, so under load they are more likely to shake or vibrate. Maybe that is what you are feeling?

My 82 Toyota 4X4 4 banger was always smooth as silk. I've seen a lot of complaints of people having their auto transmissions overheating when in 4hi on 4th gen Tacoma's, something doesn't sound right?

 

[Romer]

When your transmission temps get high, are you in Drive? I had an issue with my 200 series Land Cruiser in Drive while towing the transmission would overheat up Mtn passes. Turns out the tranny is hunting for gears in D using the computer. I switched to manual 5 when towing and havent had thee problem since. Note when in Manual 5 on an auto tranny, it will still use gears 1-5.

Note sure if this is applicaable to the Tacoma, but might be since same manufacturer

I also use OBD Fusion and monitor transmission temps along wwith several other items

 

[TacoFreak]

My 82 Toyota 4X4 4 banger was always smooth as silk. I've seen a lot of complaints of people having their auto transmissions overheating when in 4hi on 4th gen Tacoma's, something doesn't sound right?

I was just speaking from a mechanical engineering POV, that inline 4s are not naturally balanced engines. I have had more than one Toyota 4 cylinder that was very smooth too. I have not noticed any unusual vibration when my truck is in 4HI. It would be interesting to see if anyone else has noticed this.

It could be the transmission not being in the right gear like @Romer said. You could try using the manual mode and see if that helps and watch the transmission temp too.

 

[izzy]

When your transmission temps get high, are you in Drive? I had an issue with my 200 series Land Cruiser in Drive while towing the transmission would overheat up Mtn passes. Turns out the tranny is hunting for gears in D using the computer. I switched to manual 5 when towing and havent had thee problem since. Note when in Manual 5 on an auto tranny, it will still use gears 1-5.

I actually did a little experiment with this today on a trail, drove the entire thing in S1, since the trail was best at around 10mph.

I noticed on the longest climb of the trail the trans temp got up to 240F, as indicated by my Scan gauge, which was about 3/4 the way to the red bar on the cluster trans temp gauge. It never overheated but I was curious if it would stop climbing, didn't find out since I summited the peak and then we were descending.

I didn't feel like the climb necessitated 4Lo because it wasn't that steep, and I assume at 10mph the truck can just lock the torque converter anyways and reduce the heat being pumped into the trans.

RPMs were around 2000-2200, so a fair amount of coolant being pumped through, when I bumped it into D it immediately shifted to 2nd.. which seemed too low for the grade, which I calculated at about 10%.

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