Transmission Temperatures

I think it's more likely that the bean counters were able to determine that the transmission won't fail even when towing 10k lbs until after the warranty is up and thus it won't cost them anything (other than customer goodwill, maybe). But by then they'll have a new Tundra and will be able to say all the issues of the 2019 have been resolved so don't buy from someone else.

 

I like knowing what's going on but I'll admit to being a data hog.

 

my trans was touching 217 driving around town. And its 53 degrees outside.

 

I found the codes and reprogrammed the Ultra Gauge

Also. I dont want to rely on my phone when driving long distance
So I will stick with the ultra gauge

To ea h there own. Everyone should use whT they like. And are comfortable with

 

I have been monitoring my 2010 around tow, long trips, highway, ...etc.

monitoring with my Bully Dog platinum....so wherever that pulls from...not sure...but I have NEVER gone above 199 on that gauge.

most of the time I am around 190 ish...185-195...with sometimes 199...197...etc.

 

Marmalard! I did exactly as you suggested. I have an ‘18 and my brother in law has a ‘19. When I started reading over these trans/temp threads I got very curious about what kinds of temps I am running, as my 18 DOES have the external cooler. I now have the OBD app and and device to randomly check my temps (Thank you for the recommendation!) I can report that my temp sits around 185 once everything is warmed up. Heavy acceleration results in temps increasing to about 196, and then I believe the thermostat opens up and cools it back down to 185. Haven’t towed anything yet and probably won’t through the winter.

 

I am the same in my 18. 180s to 190s using BD tuner. Sometimes up to 200-205 if I’m driving fast. My upper ATF hose is hot at 194 so my thermostat opens somewhere around there.

 

Has anyone installed a cooler on there 19 or 20 tundra yet?

 

So this is an older thread...has anyone reported any issues?

Also, I read this entire thread and didn’t see any temperature ranges and max temps for the Tundra as reported by Toyota. Does anyone have those? Maybe they’re buried in another thread...but I’d like to understand the real numbers.

I saw the graph that someone posted earlier in this thread. It looks suspiciously like one that floats around the internet from a company selling aftermarket coolers and doesn’t have any references. That chart (if it’s the same) was posted multiple times in the Ford forums I used to frequent as gospel. However, the forum had Ford engineers answering questions for a while and they confirmed their transmission temps and fluid limits are completely different. Today’s synthetics are completely different than whatever fluid was used to formulate that chart years ago.

 

That may be so, ATF can probably handle better heat tolerances, however, there have been reports of folks getting high transmission temp warning towing half the trucks rated towing capacity in their 2019 Tundra.

 

That’s my experience too- at 195 or so, there is a sudden temp drop.it cycles between 185-195 unless I accelerate hard. Still playing with it to see how it acts. I am using OBD fusion and OBD 2 scanner, which works great. Great suggestion by @Greg Marmalard.

 

Not trying to stir the pot on this issue further. Anyone have bigger tires on their 19-20 yet and run the temps? I wonder if the new ones will see more of a cooking effect from big tires

 

Really? I absolutely don't worry about it. I have no monitoring. I have towed 9K several hundred miles. It still shifts fine. I trust the engineers because in this application, they know more than me.

 

But you've had your truck for less than ~15 months. How can you say it will last 15 or 20 years and 500,000 or a million miles?

 

ahh, but isnt that the gamble we all take w/ a complex, long-term piece of machinery?

Trans temps for my '14 (4.6 w/ no tow/haul mode, no extra coolers, etc.) are virtually unaffected towing vs not towing. Keeping truck in S4, temps are staying constant 190-200°F (in Louisiana heat) towing my boat, which is probly 2750-3000 loaded. Yes, this trans runs a little warmer than I'm used to, but the truck keeps temps pretty consistent. I'll service everything per the manual and see how long this thing can last! Definitely my favorite truck I've had so far, and I'm curious to see the kind of miles we'll get before anything major happens.

 

The guys I've talked to who run their GMs for a long time like to target below 185F but 190-200 doesn't concern me too much as it sounds like that's where most 2007-2018 Tundras run. However, the 2019-2020s seem to run in the 215-230 or 240 range and it's the impact of that change on long term reliability that I think is unknown at this time (and will remain that way for several years).

 

I cannot, and neither can the guy who monitors every temp including bearings, changes his oil every 500 miles, waxes it every day and cleans his injectors twice on Sunday.
There is an expectation from consumers and it differs depending on vehicle. Most Toyota truck owners expect 250K+ with OEM listed maintenance. Most will get that, as evidenced by history. Truthfully the guy who takes his truck to the dealer for service and never cares about anything but adding gas will end up getting the same longevity out of his truck as the paranoid guy monitoring everything and halving the service intervals.
I personally think that most enthusiasts here just enjoy tinkering and trying to figure stuff out and that's fine. Trying to justify that their diligence will add reliability is sketchy at best as the data just cares about the miles driven, not how it was maintained.

Now, with that said, and knowing what I know from my profession, if I wanted to drive this truck for the rest of my life (newsflash... I don't. I enjoy changing it up every now and then) it would be fairly easy to go 750K+ and beyond.
1. On day 1 change out oil filters to dual cannister remote mounted.
2. Sample all fluids every 10K, including diffs and transmission. Change oil 10K, change diffs at 50K, change trans fluid 100K, rinse and repeat.
3. Change major joints every 150-200K.
4. Change coolant, ps fluid and brake fluid every few years.
5. Belts and hoses changed every four years.

That would do it if you truly wanted to have a forever truck. Not me but maybe somebody else. Life is too short.

 

This is an older thread but wish I had found it before just purchasing a new 2020 Tundra.

Apparently Toyota has decided that temperatures below 257 degrees are fine in their transmission. And they are most likely correct. Just goes against everything I thought I knew about trans and how temperature affects them.

The heater/cooler cools the transmission enough to keep it around 207 while the torque converter is locked. And easily go up to 220 to 230 in third gear on hills.

When going over a mountain temps will spike to ~255 degrees and then plummet back down to ~207 when the torque converter locks. The torque converter will lock in second and third gears when the trans temp reaches 257 degrees. As long as you are not in first gear it the trans will not overheat (go above 260).

 

Were you towing ?

 

https://www.tundras.com/threads/2019-transmission-cooler-kit.60550/unread There have been several threads on this "issue" but this one presents a solution and has good info.

 

Jtundra. Yes while towing a 5500 pound trailer with family of 5 and gear.

Azure. Thanks for that link. Excellent information there. Going to follow that.

 

Just throw an auxiliary cooler in it and wash your hands of any more temperature concerns. You will see transmission temps drop a solid 50 degrees.

 

Good info!
How do you know this?

 

Info was from a post, looked for it but could not find it again. OP was talking about going over a mountain and watching his temps rise in 3rd gear, then all of a sudden out of no where they dropped when they hit 260.

One of the replies was what looked like a transmission testing document from Toyota showing the case where tq locks in second and third and temp is over 257.

Anyone towing with a 2019/2020 w/o a cooler should be able to reproduce.

 

It’s not that simple, many options for TC lock. If you want to see any specific let me know.

 

Will the $1000.00 out of pocket fix a problem that hasn't been fully proven yet? Lots of good info here, but i still haven't seen a definitive answer to all the great questions asked that would lead me to believe, or make a decision one way or the other.

 

I’d like to see specifics, I geek out on this stuff so any and all info is welcome and appreciated.

 

What would you like to see? There are tables for many things on 18+

 

Mostly interested in torque converter lock up control, when and at what percentage. I’m assuming since we have a flexible lock up converter the computer can control lockup percentage in a certain range.