Transmission over heat temp warning display...

Now I could see that. But, back in 2007 wouldn't they have touted it with higher numbers if they could have?

 

Toyota does uses high gauge metal and high strength steel but have no clue as to the strength compared to a domestic 3/4 ton. My feeling is the Tundra is way over engineered compared to a domestic so its unlikely they stopped at the frame. I would put the frame strength at surpassing and the domestic half tons and come close to the 3/4.

 

Then again, if it had a 3/4 ton trucks payload and was rated as one but only towed like a 1/2 ton they would have been dead in the water. You may be onto something @timsp8

 

Nissan Titan XD comes to mind...

 

Remember this commercial.

https://youtu.be/R9jaOROeYII

This one gave me a good laugh.

https://youtu.be/xRZJ2wnldxQ

 

...and they are gone from the NA market for 2021.

 

*UPDATE*
Took the "young adults" up the mountain this weekend, no luck with any moon shots but some nice pre-dawn and sunrise shots the colors were pretty awesome.

Ok so this time at the bottom I got the truck into hi 4x4, came to a stop put it in neutral and put in in lo 4x4. Mind you this time we had 5 people in the rig instead of 2 so I was carrying more weight to top if that makes a difference...

1. Going slow and in lo all the way up no problems no light/warning, even went a little further this time
2. I don't know who said it but I have to disagree going down in lo gave me way more drag I barely needed the brakes.
3. Going into the dealer I'll let you know what they say, I'm on the the fence if I should push for a fluid change, I have this fear of them messing it up...

pics and vid for your viewing pleasure...

https://www.youtube.com/watch?v=PYWi1u97rNY

 

Thanks for the update.

 

I would try to get the fluid changed. The high temp warning comes on at 302F and ATF degrades quickly at that temperature. Ask them to save a sample so you can have a look at it. It's probably pretty dark in color. Dont say anything about driving it in 4H on a steep grade. You don't want to give them a reason to blame you. Just tell them you were driving the truck and the high temp light came on and said to bring it into the dealer.

 

Hoping this closes the thread. I’ve said it in other posts, I’ll never tow more than my motorcycle so I’m assuming I’ll be fine.

 

I’m curious if you get the warning light there are no codes retained in the ECM memory?

 

In my opinion, there is nothing "normal" about 300 degree trans fluid temps... under any driving conditions or speed.
You should be able to flog the shit out of your truck in 2wd, 4wd, slow, fast, etc... without overheating the fluid. ever.

I have never had any weight in my truck and it was running 220+ pan temps during normal driving. Now with the aux cooler it is in the 170's.

 

Slow and 4 high up hill will overheat it with the cooler too. Slow means little to no airflow, and that means the cooler isn't going to be very effective.

 

I would still be surprised if this were the case... and would love to see examples of it with '18 and older trucks.
Ive stood in front of my truck with the engine at idle and the fan pulls a tremendous amount of air through the grill... enough that I felt no need to install the fan and shroud that came with my aux cooler.

 

The thing is we don’t know what the range is to trigger. The dealership did what the manufacturer recommended not much more to say.

I’ve proven the truck performed flawless in 4 lo on my second run. And I could of probably made it in rwd without issue, but why not use the 4 lo.

I’ve documented the incident, truck runs as it’s suppose. The “normal” might just be that, it’s normal to get warning letting me know my dumbass should of been in 4 lo if I wanted to go that slow...

 

302F according to TIS. At 302F serious trans damage can occur if you continue to run it with the warning. Your trans fluid isn't dark so the warning was on for only a short period. Your probably not going to have the issue again because you know how to avoid the over heat situation.

 

My last truck was an 18 Tacoma TRD Offroad. (hated it and not even worth the mention)
Prior to that... I had a long list of HD trucks as daily drivers... 2013 2500HD gasser, several dually's and other 2500's prior to those.

I couldn't be happier with my Tundra... and if anyone actually compared the numbers/specs of those older HD trucks... our Tundras are every bit as much truck as the duallys and 2500HD's of not long ago. In some cases... the Tundra is MORE truck than the older dually's were.

Compare...

Curb weights
brake rotor/drum diameters
differential ring gear diameters
horsepower/torque numbers


The ONLY thing I've found lacking in the Tundra is the rear leaf springs... and that is easily upgraded/corrected. (At the expense of ride comfort)

 

I towed a small tractor over the weekend, up and down the hills here in CT, on the highway with just the trailer pulling a long grade temps got to around 243°, in D. With a load @4500lbs in Tow/Haul and S4-S3 temps in the 220's. First time with this much weight and the OBD app, seems to dissipate the heat better when the rpm's are up. my $0.02

 

I would agree that the rear leaf springs are the weak link and of course missing tranny cooler. That's why at just over 2000 miles I installed Nicks cooler kit and a set of black (1500lb) SumoSprings.

I now have the confidence that my truck will handle the load and not overheat the transmission!

 

My cooler went on last week at 3000 miles.
Transmission temps have not gone over 200 degrees at the converter since.
Pan temps usually settle around 175-185 depending on driving conditions.

I'm super happy with the results. Rear springs or bags will be done eventually also.

 

I also have the black Sumospring installed. I put about 1,000lbs of flooring in the back and couldn't even tell it was there.

 

I'm not so sure TIS is the factor in play here...
Take a look at the screen shots from the owners manaul.

On the message I got (the first pic) they certainly are not worried about it, pull over let it cool down carry on. nothing about going to the dealer. This is the message I got, I did not pull over for it to go off I kept going and about 1/2 mile it went off. The next 2 are not what I had but interesting...

 

TIS is from Infostream. It's a Toyota data base that technicians use for vehicle repair.

When the warning is indicated the trans temps is at 302F or above. The warning will disappear if the temperature drops below 302f.

 

Yep I know about the software I have it and have used it. My take away is that the owners manual basically says if it hits a set temp pull over and if it cools down proceed. Nothing about you've boiled your fluid take it into the shop etc...

There is also the transmission protection function how does that come into play?

If you are saying that the TIS is telling the ECU to throw the warning message when hitting 302F the question is, is 302F a bridge too far? Because Toyota is basically saying no... just pull over let it cool down and proceed.

I'm much further down the rabbit hole on this than I want or should be. I think the major take away is if your are in 4 wheel and going slow you need to be in low. If you are in 4 wheel and going fast you need to be in HI. It just never occurred to me that being in Hi while going slow would heat things up more, but it makes sense.

 

If your having the warning come on a number of times it will degrade the transmission fluid quickly. WS fluid cannot handle repeated temps at 302f. Because you had the warning once there isn't a concern but I would certainly monitor the temperature to know what my temps are running. Anything above 250f will shorten the life of the transmission fluid over a long period of time. Toyota states that WS fluid is good for the life of the vehicle but only if used in normal service. That the out if a warranty issue arises.

 

I think that makes total sense

 

I have a question for you in the know.

Is the 302f high temperature warning originating from the pan or the torque converter?

 

I think if driving slow in 4H, the torque converter may not have a chance to lock and that would increase the ATF temperature.

In 4L, I guess it's like being in gear all the time and basically torque converter is locked (or locked more often?) or out of the equation so not much heat is genetated. Experts can correct me but that's what I would do if I was designing the damn automatic transmission. Oh wait, I would never design an auto trans just manual trans for me. I wish Toyota had a manual trans V8. All my Tacomas were manual.

 

I 2nd the vote for a manny Tundra! I almost bought a Tacoma just for the stick shift but couldn't live with the small space (relatively speaking). My son has a 2000 manual Taco that I drive occasionally just for fun.