Transmission overheating in 4HI when going uphill - Toyota's answer (or non-answer)

[Chris_2025OR]

How it happened:

I was driving on a grated 2 lane wide dirt road in 4HI when the transmission overheated. I was loaded down with about 400lbs of gear and 2 people, 285/70r17 tires aired down to 20psi (2k miles on the truck.) I've done that road in a built and loaded down 4th gen 4runner and a F350 on 37s with a 3,000lb truck camper, and they both handled it no problem. I crossed an old Chevy Astro van that was coming downhill, and it made it. All this to say I expected my brand new TRD Off-Road Tacoma to be able to do this road no problem. I could see the transmission temp gauge start to go up as soon as we started going uphill, then the temp gradually climbed until it reached the red about halfway up the mountain at about 6k feet elevation. I lost power and it kind of felt like the truck stalled. I put in in 4lo and the transmission temp dropped a little below the red and stayed there consistently as we continued our way up. But 4LO was painfully slow for this type of road, and I was just itching to actually make some way up the mountain. So, I put it back into 4hi to see what would happen. Sure enough, within minutes the transmission temp was back up to red and the truck stalled. So I put back into 4lo and stayed there until we made it to the top.

The road it happened on:

I brought it to Toyota and this is what they said:

I asked the service advisor for his advice because the problem I had was real, and I expect that if it happened at 2k miles, chances are it'll happen again. His advice was to use my phone to record everything I can in real time and submit the evidence to Toyota. But the thing is I don't want to have to "prove" anything to Toyota, I just want the truck to work the way it's supposed to.

Has anyone else experienced this? What does the 4g community think? I'm thinking maybe I should have bought a 3rd gen...

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[CrispyTacoLover]

Was 4wd actually needed?

 

[Chris_2025OR]

Was 4wd actually needed?

No but the rear end was sliding around on the washboard in 2hi, so it's a which do you prefer type of situation; super slow in 4lo or not enough grip in 2hi. I shouldn't have to pick one or the other in my "offroad" truck.

 

[gasgasman]

But the thing is I don't want to have to "prove" anything to Toyota, I just want the truck to work the way it's supposed to.

How is the technician supposed to duplicate the concern?
They can't fix what they can't find.

 

[BAQ717]

Do the trip again, document it with video evidence and send it to Toyota. Only way you’ll get a resolution.

 

[Miqie]

Do the trip again, document it with video evidence and send it to Toyota. Only way you’ll get a resolution.

Also, you might switch the dash display to where it shows the angle of the truck on grades. I'm not near my truck at the moment, so I don't know if it gives a numerical readout of the slope. Also note the outside temp that you're driving in.

 

[wutheck]

Yes, many of us have experienced this...
https://www.tacoma4g.com/forum/thre...on-overheating-on-long-climbs-off-road.12606/

 

[Bcphoto3]

Yes, many of us have experienced this...
https://www.tacoma4g.com/forum/thre...on-overheating-on-long-climbs-off-road.12606/

Me too out West. Pulling 3000# trailer and went to 4Hi because of road (only for couple of miles) and the engine slowed down and I got a Too Hot Transmission warning.. Sounds like a problem Toyota needs to address..

 

[Miqie]

Does the transmission have a radiator?

 

[Wife bought my 24 TRD]

How it happened:

I was driving on a grated 2 lane wide dirt road in 4HI when the transmission overheated. I was loaded down with about 400lbs of gear and 2 people, 285/70r17 tires aired down to 20psi (2k miles on the truck.) I've done that road in a built and loaded down 4th gen 4runner and a F350 on 37s with a 3,000lb truck camper, and they both handled it no problem. I crossed an old Chevy Astro van that was coming downhill, and it made it. All this to say I expected my brand new TRD Off-Road Tacoma to be able to do this road no problem. I could see the transmission temp gauge start to go up as soon as we started going uphill, then the temp gradually climbed until it reached the red about halfway up the mountain at about 6k feet elevation. I lost power and it kind of felt like the truck stalled. I put in in 4lo and the transmission temp dropped a little below the red and stayed there consistently as we continued our way up. But 4LO was painfully slow for this type of road, and I was just itching to actually make some way up the mountain. So, I put it back into 4hi to see what would happen. Sure enough, within minutes the transmission temp was back up to red and the truck stalled. So I put back into 4lo and stayed there until we made it to the top.

The road it happened on:

I brought it to Toyota and this is what they said:

I asked the service advisor for his advice because the problem I had was real, and I expect that if it happened at 2k miles, chances are it'll happen again. His advice was to use my phone to record everything I can in real time and submit the evidence to Toyota. But the thing is I don't want to have to "prove" anything to Toyota, I just want the truck to work the way it's supposed to.

Has anyone else experienced this? What does the 4g community think? I'm thinking maybe I should have bought a 3rd gen...

Happened to me in 4 hi on the beach. Running 255 80 17's with full air pressure. I have not tested it again but I bet it will happen again. My truck carrier some weight, but not enough to make 4 hi worthless for any length of time.

 

[BAQ717]

Hopefully it is something that can be addressed via a software update. Possibly a thermostat that controls the flow of coolant isn’t operating appropriately. Otherwise, it seems the easiest fix would be to upgrade the radiator/integrated transmission cooler. I haven’t had this issue but definitely following as it seems pretty common on this forum.

 

[Gfenza89]

These transmission SUCK in these 4th gen’s. At least yours doesn’t shudder and jerk and buck and vibrate like a kid learning to drive stick shift ..

 

[BAQ717]

These transmission SUCK in these 4th gen’s. At least yours doesn’t shudder and jerk and buck and vibrate like a kid learning to drive stick shift ..

Mine is smooth with the exception of the first cold shift or two… my BMW with the lauded ZF8 was the same way on a cold start. If your transmission is acting like that consistently then you have a problem.

 

[Duck Amuck]

Did you try putting it into Tow/Haul mode? I've seen people say that helps with transmission temperatures.

 

[Bcphoto3]

Did you try putting it into Tow/Haul mode? I've seen people say that helps with transmission temperatures.

Mine was in Tow/ Haul mode most all the time while towing. You just have to remember to turn back on after you stop.

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