Typical transmission temps?

I agree that it’s early however look at the amount of 2019’s and up Tundras on this forum that are towing well beyond their capabilities (weight wise and payload wise). If it were a severe problem there should be more problems (for 2019+s) in my opinion simply because many owners don’t understand that fact that modifications lower the weight that you can tow. In addition to fluids and or items loaded in the truck or trailer. Many of the towing I see done on this forum, I consider severe duty not normal. Hence why I feel more problems should be seen by now.

I have read the Toyota engineer post. I am NOT discrediting the poster or the engineer in any way but there simply isn’t enough info to make an accurate judgment. He simply may be bitter because he was overruled…I honestly don’t know. However I would love and be highly interested to hear more than one engineer and more than a couple of oil reports.

I am not saying I am conclusively right and anyone is conclusively wrong here…I am skeptical.

 

No, I really don’t think that engineer is bitter because he got overruled. He added one to his own truck. This suggests he honestly thinks it was a poor decision.

Can you link to some posts that show what you consider severe duty towing with a 2019-2021 Tundra? I remember seeing one guy hotshotting with a gooseneck trailer well above the truck’s towing numbers. That was a 2015 double cab though.

 

or ... if the 22 doesn’t have a transmission cooler ... it could just as likely mean that Toyota is continuing to follow the increasing market demand for trucks as commuter cars. Pretty soon a person may need to buy an HD truck just to do truck things.

 

The engineer being overruled was sheer speculation… It can be for a number of other reasons as well. Point being an in depth conversation would have to be had with him to come to any conclusion.

In regards to examples I don’t have the time or energy to search so I will concede there. However towing near or at max is not normal service. Going off roading is considered severe service (dusty roads according to Toyota’s maintenance schedule).

 

I'm still trying to decide as to how I want to proceed. I am a mechanical engineer, so I know full well how excess heat can deteriorate parts, but without knowing the material specs of the internal components of the transmission, such as seals and solenoids, I can't comment too much on that. It is not that difficult to select components that can easily handle this type of heat, but I don't know what they used.

I do tow an approximately 4100 lb trailer with my Tundra. When towing, I am running a good 15 degrees warmer in the transmission fluid than when I am not towing (not towing I max out at about 204-208 deg F and towing I'm usually around 222 deg F when I use S4).

Toyota says to just tow in D and T/H mode, which puts me up around 230 deg F, but I feel better in S4 (more power, less hunting, lower temps). Given Toyota's direction, I kind of want to stop monitoring the temperature (and therefore stop stressing about it) and just roll with it. I have an extended warranty so if the transmission goes out within 10 years it will be on Toyota's dime, though clearly that's a scenario best avoided.

I am not against adding a transmission fluid cooler, and I definitely wish Toyota had just left it in, then we wouldn't be having this discussion.

So in summary, I am floating somewhere between not worrying and letting the warranty take care of things if it fails, and just biting the bullet and adding a transmission cooler.

 

well as stated earlier it is the same transmission used since 2007. I doubt any elastomers were changed. so at one time Toyota thought it need a cooler but now they don't and coincidentally Toyota had to revise the component where the cooler was located for AC purposes. Our elected officials demanded the freon spec change so maybe the missing cooler is on them.

 

Fair comments, and all I can do is speculate.

I will admit that I have had to add features to our products not because we needed them, but because the competition had them. It could be that when the 3rd gen Tundra came out and they made a big deal advertising the towing limits, that they felt they had to include a transmission oil cooler to be taken seriously. Now that some of the competition has been dropping the coolers, Toyota can too.

They also no doubt have a TON more information about the life of these transmissions than they did back in 2007. Adding a cooler does fit in with Toyota's typical conservatism. I have no idea how many 2007-2018 Tundras were delivered without the towing package (and therefore without the cooler), but no doubt there were a good amount of those and I haven't read of those having transmission problems (and I'd wager a guess that at least some of those owners DO use those to tow, but no real way to gauge that number). To me that says that a Tundra without an oil cooler that does not tow really isn't going to be an issue. That brings it around to folks like me, who do tow, and trying to determine if the situation is acceptable or not. And I still don't know. I just know I'm not losing any sleep over it (yet).

 

My position is pretty simple. I operate my truck, maintain it, and tow according to and within the operating parameters specified in the owners manual. If I felt like the transmission would fail prematurely without doing after market modifications, I would sell it and get something else.

 

I get it. myself I would rather have it, cooler the better I would think

 

Amen, well said. I think most people get caught up on reputation, and forget that Toyota still answers to share holders that are looking to collect vast amounts of capital in the market economy... just like every other car manufacturer that we hate. The competition builds their trucks so poorly that the Tundra would need something far larger than 3 years worth of suspect transmissions to pull even. With the glow of the new 2022/4th gen, it won't even matter if/when it is an issue, because they will say it's been solved with the redesign. They have a built in excuse.

This is just a calculated risk by Toyota, one I want no part of.

 

Define "premature". It's probably a safe bet that most GMC, Chevy, Ford, and Dodge folks probably put their number far lower.

I don't think anyone here is arguing that the lack of cooler makes this truck less reliable than the competition. All of the concern on this thread comes from folks that have ambitions of seeing their rig go 500,000 or more. There are no other trucks on the road that even come close. If I can pay a couple hundred bucks to increase those odds significantly, I'm happy to do it. Selling my truck and getting something that could never measure up makes zero sense.


Edit: Forgot to add, my dealer is adding a cooler before it leave the lot next week, so this isn't an aftermarket mod, and I'm not the 1st one to request it. Even if I did it the installation in my garage by myself and then the transmission went bad under warranty, Toyota would need to prove that the addition caused the failure. If they are arguing their case based on the current scientific understanding of heat and transmission failure, I like my chances.

 

You're only paying a couple hundred?

My main issue with adding the cooler is the cost. 1000$ seems to be the cost. A whole new transmission is what, ~$5000?

Pay $1000 for sure to maybe not have to pay ~$5000?

 

Wow. That definitely counts me out. At 7k miles/yr that would take me to about year 2092. And I probably only have another 20 years before they take my keys away.

 

What is your dealer charging you to add the cooler?

 

You could probably install a cooler for under $500. Cooler, toyota transmission thermostat and run rubber hoses vs the steel. make you own plate. Sure it would take time but not money. this assumes you are mechanically inclined.

 

I went back and read that post again. To me, it’s pretty clear what his conclusion is, why he thinks Toyota did it, and what he did to his own truck because of it. I’d love to hear more about the heat-related failures Toyota has seen that he mentioned, but I’m not left wondering anything about what his very much informed opinion is.

I don’t see where an in-depth conversation is needed to make a judgement call about what his statements mean. Sounds kind of dismissive to me.

I didn’t mean to imply these cases don’t exist. I see lots of threads where guys ask which 30’ camper is best for the Tundra. Most of those guys seem to get talked out of it pretty quickly. I do see examples every once in a while of someone overloading their bed for a mile or two from Home Depot with too much gravel or for a trip to recycle some scrap metal.

I also just read the maintenance schedule, and yes if you go off-road, they tell you to check steering linkage, cabin air filter, diff fluids, ball joints, drive shaft boots, body nuts/bolts. Prescribed maintenance for towing differs. Where do you see the term “severe duty”? I’m not seeing that in the maintenance guide that came with my 2021.

Point being, I think far fewer people are being hard on their trucks, at least on a regular basis, than you’re claiming.

 

In regards to the engineers statement I am going to respectfully agree to disagree. Personally I am not going to base the need for a transmission cooler or not based off one statement by one engineer. Everything in life has more than one truth. So you are correct is saying I am dismissive but only to a certain degree. I am willing to listen wholeheartedly but again not make a conclusive decision. Multiple engineers providing the same data and explaining why the internals would not be able to handle the temps that Toyota said is “okay” would be a different story…I would purchase a cooler tomorrow.

Severe duty…I thought I read in the maintenance manual that taxi service, off-roading, and towing regularly that it was. I believe you, I was mistake then.

However based on my experiences when using a vehicle near its highest capacities puts much stress on it. Yes it can handle it but it’s going to wear things out quicker period. At which point it requires more maintenance and a different driving technique. The bottom line here is for me is this…even with a 6k TT trailer (that is well within the Tundras limits AS IS) it going to be much closer to max with a family of three, food, fluids, ETC ETC than many people believe.

And I not only basing my opinions only off of these forums. Many vehicles that trailer in my area are typically under vehicled, not set up properly, and drive aggressively for towing.

Using the truck as a truck is not being hard on it. But when at or near max capacity and driving it like it’s a sports car will destroy any truck…commercial included.

 

I didn’t base my decision to add the cooler bc of that anonymous engineer’s statement alone. I also monitored my temps prior driving in hilly middle Tennessee. I would see 225-230°F unloaded alone at the speed limit on the highway.

For me, I just put far more stock in what someone says off the record to someone I have no reason to distrust when they have absolutely nothing to gain from it versus someone speaking in a PR capacity on behalf of the corporation.

Yeah, I’m a bit over capacity at this point when we go camping. And I off-road a bit. Nothing too crazy but I’m switching to Amsoil for everything but the transfer case and sticking to a somewhat accelerated maintenance schedule.

 

I believe cooler deletion was a management decision, not an engineering decision. If there was a slight redesign necessary for a different AC condenser and maybe required a redesign of the trans cooler, a number-cruncher in management naturally asks "What are the numbers for all of this?"

Engineering and management go back and forth discussing the performance/reliability pros and cons, and cost (which always has its hoof in such discussions).

Management calculates the $$$ saved deleting the cooler on not only the Tundra but the Sequoia and Tacoma V6 also. Let's say 200,000 units/yr for all three, $200 per unit. That is $40 million saved each year.

That's very attractive, that lifts upper management's skirts. Engineering is tasked with making it work, hard to pass on $40 million per year, especially when Toyota America is building a new Tacoma plant in Hermosillo, retooling San Antonio for the TNGA-F Tundra and Sequoia.

So engineering does what they're told to do or management will find someone else to do it. Engineering maybe tunes the auto trans to stay locked more often and here we are.

I find it curious that with the chasenicholas kit nobody is having air conditioning problems and getting better trans cooling, so it's obvious Toyota could do what he did but chose to save $$$$.

 

I am sorry I was not implying you based it off one statement and going off our discussion and previous posts I would say that you though it out. And I respect your experiences of 230 trans temps and will definitely keep that in mind.

Also a well made point on the engineers perspective…makes sense.

Amsoil makes some very good products and I still think they make the best gear oil. I don’t put many miles on my truck but in the next year I would like to swap the gear oil out.

 

Winner, winner, chicken dinner. Plus they will get to use all of the money saved to help pay for the line switch. If you don't believe that Toyota looks at every cent; one of my customers is owned by Toyota. I raised the price of a machined part 15% since the last price change was over ten years ago. The change in price was only $0.18 but I never saw another order for that part. Toyota is a very cost conscious company.

 

I owned a 2017 F250 6.7 Diesel. I hope we can all agree it is a heavy duty truck made for continuous towing. Transmission had its OWN cooling system. When I first got it I almost crapped my pants when I saw 195F trans temps. I was like this thing is going to cook. I towed with it for 14K miles but it was to big, to rough, blah blah. In all of 14K miles not once did my transmission temperature go above 195F engine coolant temp hit 220 at times, but trans temps was pegged at 195F once it was at temperature. Appears Ford engineers not as good as Toyota since Toyota transmission temps don't alarm until 290F. It was funny in my F250 owners manual they would talk about 250K mile service. I guess if you can live with 100K mile transmission, nursing it when towing in S4, may have to pull over if trans temp alarm goes off then no cooler needed UNLESS toyota engineers using a 2007 design is smarter than the Ford engineers who say 195F in heavy duty truck is enough for us....

 

Do pre 2019 Tundras have the "tow in S4" in their manuals?

 

I think they say tow in S5. But it says for engine braking efficiency or something.

 

I just looked up the 2018 and it says to tow in S4 and tow/haul, same as current. And also same as current, this information is spread across a few different pages and so doesn’t give very clear guidance overall ...

 

The manual isn't very clear, so I contacted technical support at Toyota and they wrote back (I can post the email here if it's helpful) that towing should be done in D with T/H mode activated.

 

You are correct for using engine braking use s4.

 

I not questioning in anyway but that info that Toyota gave you seems counter intuitive…no?

 

Kia says everyone in Canada has to follow the severe service maintenance schedule because of the cold. With respect to our Corolla, Toyota says only taxis and similar are severe service. But if I let the car go 5000 miles between oil changes, it's pretty black so I'm doing 3000 mile oil changes in the Corolla. Probably stick with 5000 mile intervals in the Tundra since Toyota says it can go 10,000 miles.

 

I just read a post here that, if I interpreted it correctly, says that someone with a 2018 with the tow package (and thus with the cooler) sees 230 when towing. So maybe temperatures on the 2019+s aren't that much higher than previous years?