19-20 Discussion on Missing Ambient Cooler

Lol Toyota engineers tell me I can pull close to 10K with the truck in stock condition.
I pull around 7K once a month.
I am an engineer and routinely use heat exchangers in my designs so I know a bit about fluid dynamics and thermodynamics.
There is no "magic temp" for transmission fluid. Unless you tow heavy all day every day you should have no worries. A trip over the Rockies for several hours, out of a year, is not even a blip in the data curve.
With that said, I don't even think twice about temps when towing and I damn sure don't use any app to show me performance data.
My truck should last well over 200K with no extras and minimal maintenance.
Good luck.

 

With the ambient cooler I won't need luck.

 

It won't hurt. But if you are gonna add one, might as well add two or three, that way you will really have piece of mind lol.

 

So as an engineer with experience in thermodynamics you don't believe that high operating trans temps can have an impact on the longevity of the transmission?

 

Define high temp, define duty cycle, define application, define operating parameters.

This is what determined the design that is being used.

 

So from 2007 to 2018 Toyota engineers decided that an ambient cooler was required then suddenly in 2019 they realized their mistake and removed it. The explanation given was that through a change in trans software they were able to control trans temps to an acceptable level. The 07-18 has an normal operating temp that would stay below 210F under extreme conditions while the 19-20 has operating temps north of 250f and some have had the high temp warning indicated which is 302f. WS fluid will start to degrade at temps above 250f. Reinstalling the ambient trans cooler will prolong the service life of WS fluid which will have a positive effect on the service life of the transmission.

 

I have a 2018, but if I had a 19+ I’d definitely add a cooler. It’s not that hard or expensive for a little piece of mind. What I don’t get is everyone that says, after there was one for 12 MY, Toyota knew what they were doing when they decided it wasn’t needed anymore and you are wasting your money. It’s your money. Those same people aren’t going in lift threads saying Toyota knows what they were doing with stock suspension. Both are modifications to the stock truck using their own money.

From what I’ve read nothing changed. Same fluid. Toyota claims they changed shifting, but people are getting higher temps than 07-18s real world. People talk about fluid temp, but what temp can the seals manage?

The trans went out in my 2010. It was holding gears, hesitating to shift from P, wouldn’t go into R sometimes, got a CEL for solonoid D. If it gives anyone piece of mind, I was still able to pull a ~4000lb uhaul from MO to TX before it was replaced. Never ran right again after I got the remanufactured replacement though. But if yours goes out it could still get you home.

 

With due respect from another engineer (BSAE, MSME) with 32 years experience, this change does not look like an engineering decision.

From an engineer's viewpoint, nothing is accomplished with the change...transmission performance is not improved and reliability/longevity is not enhanced. The only benefit from eliminating the auxiliary cooler is cost reduction, so we can guess whose fingerprints are on this change. It's unlikely, IMO, that engineers suddenly realized they could reduce unit cost $$$ by relaxing their previous design basis (no apparent change in fluid or transmission?), and subsequently sought to make the brand more competitive by sacrificing their built-in safety factors. But...in the end, the bosses win.

No one is trying to convince anyone they should add a cooler. If an owner is towing regularly and heavy without an auxiliary cooler, adding an auxiliary cooler would be wise imo. Anyone that doesn't tow, and/or is convinced that deletion of the auxiliary cooler makes no difference, then addition of a cooler shouldn't be a concern one way or the other.

I plan to add an auxiliary cooler to my 4.6L. Not because I think I'll need one to drive into town tomorrow, but if/when I need to tow to the owner manual limits, the truck will be equipped for it. Think of it as increasing the safety factor from the "no tow package" design basis, or, as building in redundancy.

 

I have a 2018 with stock cooler setup. I tow a 23bhs winnie. In south texas heat i run 185 to 205 with cooler open.

 

After seeing how horribly fucked up the 16+ Tacoma is with its mismatched engine/trans/gearing problem... and how they decided it was OK to run an automatic transmission up to 301 degrees before a warning is triggered.... I put very little faith in Toyota "engineers".
I will trust my past experience and common sense instead... as its never let me down.

 

If you tow a lot, you can do a lot of damage in 6-7 years. The cooler looks easy to remove if you ever have to go in for warranty work.

 

That was it thank you! I also had the wrong PID numbers.

 

Devil's Advocate:
From an engineering point of view, I constantly try to make circuits simpler. If I can eliminate a component by making a program change, I will because you reduce complexity, eliminate four potential leak points and you save weight and free up space.
Now, I have yet to sit down with Toyota engineering team and ask them why they eliminated it. Maybe someone else has or they have some official document?
While the internet contains a lot of true stuff it is really good about spreading rumors too.

And yes, if I were pulling more than once a month and my temp gauge was 250 I would add an aux cooler or two.
Right now I don't even think about it.
Where I live, Tundras are popular work and contractor trucks. I saw a new Platinum pulling a dual axle dump trailer and those are usually reserved for 250 or 350 trucks.

 

Yet you bought something designed by the guys you don't trust....

 

Took my first camping trip yesterday, pulling around 4200 lbtrailer , outside temp 82 to 86 f , tow mode on and S4 selected , speed 55 to 60 mph most of time , trans temp 215 average , torque converter temp 217 to note that it went up to 229 when stopping for tolls and accelerating and goes down to 215-217. This is going from Massachusetts to Vermont , so hills and flat at a time .
On the way back from Vermont to ma , we had rainy weather and outside temp was 64 and then went up to 78 . Trans temp was 212 on average and torque 214 with peaks at 224 for a very brief time when accelerating from a stop and then back to the average

After multiple trips this summer towing close to 4500lb , I can say that I'm Averaging 215 transmission temp with torque around 217 seeing up to 230 when stopping and accelerating and goes back to 215-217 .

 

“Regular” driving today in heat of day ... about 5-6 hours.

101-103 ambients at 3300-3600 ft elevation.

coolant temps stayed around 201-204.

Pan temps stayed in range of 225-228.

this was very long runs at 80 mph. Some acceleration to pass. Some slight inclines.

stop and go actually cooled the pan temps off to 209-215.

had cab packed with gear and people.

it looks to me like the puck warmer/cooler is managing some heat . Some. The temps didn’t runaway.

couldn’t see a difference with tow/haul mode off or on.

 

Here is a csv containing data from my one way camping trip showing it staying at 215 average when towing 4000lb . This is all MA flat

 

I hear you , however , I don't know about choosing GM over Toyota .
Look at all the issues with the 10 speed GM and ford transmissions have , the 8 speed ain't any better.
I tow 6 to 7 times a year , I will be asking dealer to perform drain and fill when I hit 30k .
If I tow heavy year round , I would install a cooler like the other guys did and call it a day.
If you look at ford trucks , they are too running with high transmission temp on their heavy duty trucks .
I am not too worried about it , if Toyota design is bad , then we will start seeing failures on the 19 and up and they will end up fixing it same as they did with the rusty frames .

 

Some thing everyone seems to be missing. Lets say you have a problem with your transmission and you have installed the aux tranny cooler. When you bring your truck into your Toyota dealer all the service manager cares about is getting paid for the work he is about to perform. He isn't looking for a reason to not do the work. On the contrary, he wants that tranny job. If the cooler has been installed correctly and you didn't mess up during the install by kinking a hose or not getting the fluid level correct the dealership couldn't give a rat's ass. The tech doing the work would check techstream for a clue on the cause of the failure. If the problem isn't related to the cooler your golden. The new tranny gets ordered from Toyota and the old one gets sent back as a core. The sevice manager's only concern is getting paid from Toyota and if everything looks good he would be more than willing to do the work. Remember the dealership isn't owned by Toyota. It's an independent business approved by Toyota. You would be amazed with the "tricks" service managers use to get warranty work approved.

 

I've heard of a couple GM 10 speeds with seal leaks but other than that they seem to be much better than the 8 speeds. The Ford version does have some issues with the shift mapping.

 

[QUOTE="SomeGuy4,

I wonder if the 2021 is going to have an actual external tranny oil cooler? The website’s literature is misleading if it’s not there.[/QUOTE]

I doubt it will have an actual cooler, most likely the same as last two years. I would call Tundra's literature misleading starting 2019.

 

Except they have NO IDEA what's supposed to be there!

I noticed the lack of ATF cooler mack in March of 2019 when I bought mine. I took back and they had to put it on the lift and three techs scratched their heads at what they were looking at and finally when to manual and saw everything was a it should be.

I don't know if aux coolers are on their radar now with all the talk about lack of them on the web. I'm sure there's an element of backing out of warranty if any changes but a cooler can't possibly cause any negative issue if employing Toyota parts.

When did they have an actual separate ATF cooler? Didn't they run it through the AC condenser for a few years? Still baffles me they would make such a tried and true plain ol' ATF cooler obsolete. Retooling even if eliminating is not free. Especially when they could charge us for it! Ask yourself if you'd have paid an extra $500 for a HD factory installed ATF cooler? it's a no brainer and had no impact on bottom line.

I still want to see Toyotas discussion about this change...

BTW I took my 2019 for 20 miles of rolling hills at 35-65mph. 70° ambient temp and got up to 210° F. Stayed around 190° to 200°. Engine temp was 190° max. I quit taking temp towing as watching north of 220° was distressing.

I'm gonna install an ATF cooler as I tow a 7000lb Airstream full time...and it's been a hot summer with miles to go!

Greg

 

Hey Greg, you still have some of the towing package. You have the larger battery and alternator, integrated brake controller and hitch. The cooler was removed because of a change in the AC freon to R1234YF. Testing showed that the Tundra can still handle light towing and since the new Tundra is coming out no point in dropping money into a model at the end of its life.

...and your right that most techs don't even know it's gone. When I bought my '20 I had no idea that it was missing and when I talked to my buddy who is a Master Tech and mentioned to him about the missing cooler he didn't have a clue either. His response was "really?".

 

What new model? Looks like 2021 is the same model yet again....so a 2019 not the end of the line. Toyota is stalled on the Tundra man! I was hearing big changes for 2020 and it'll be 2022 if then before they shelve the 3rd Gen....

Face it armchair engineers on this forum have figured out a "better" way. The parts are already manufactured and readily available.

An ATF cooler, any fluid cooler, is old school technology. It's in the books perfectly understood.

IME Removing it costs MORE as you have to test it sans cooler and crunch data. Our costs for parts is ~$500...what do you think it actually costs Toyota? Maybe $50? Again they are still made for other years so simply increase production...and charge us! I don't even recall what I paid for mine! If it was $1000 more...so what?! I had a down and a monthly payment budget. Most people are making payments of 48-60+ month and $500 is ~$8 a month! Would you or anyone walk away from a deal for $8 a month?

I go back and forth about it figuring Toyota did due diligence but then figure... what's the point? It's like removing the radiator! Maybe it can run ok through the warranty period without all the fussy water hoses etc...lets do a few tests and see!

 

Greg, what year Tundra do you own? kind of curios you don't have it in your profile.

 

2019 TRD OR Double Cab

 

The new Tundra was slated for 2021. There was some delays then covid hit which pushed it to 2022. Actually when the public new of the new Tundra it was speculated to come out in 2020. The 2019 and 2020 were suppose to be the last gen Tundra. No way they were going to design a new aux cooler for a outgoing model.

 

It took a guy here an afternoon to cobble some Toyota parts together to design one! Heck I had figured it out by looking at old part catalogs!
Plus they could have figured it out way back early in the model cycle....

It's just a weird situation where they seemed to over think it....

Re: Delays on new model....Could you direct me to actual facts on new models? I see tons of rumors but nothing firm.

Thanks!

Greg

 

Re: Delays on new model....Could you direct me to actual facts on new models? I see tons of rumors but nothing firm.

Thanks!

If you go to www.toyota.com you can build a 2021 Tundra there, should answer some of your questions.

 

I think he means the remodel, most likely 2022s. I don’t think there is any solid info yet, only speculation.