19-22 Tundra Owners Transmission Important

This over filled transmission from the factory makes sense. I bought Nicks cooler kit in June, and before starting the install I decided to check the level. After leveling the truck and proper temperature, removed the level check plug and much to my surprise a pretty good stream of fluid ran out.

At the time I just reinstalled the plug and went on with the business of installing the cooler. In hind sight I should have let it go to the trickle and measured how much it was overfull.

Now I have a tranny cooler and the proper fluid level, all is good.

 

Ignorance is not going to save you with the warranty on that.

 

I just traded my 2019 4.6L for a 2017 5.7L because I thought it ran too hot. I used a ScanGauge2 to monitor. 220 to 240 F is too hot. The dealership wanted $1500 to add a cooler, it was cheaper to traded down 2 years and no TSS.

 

Do the transmission even have a dipstick or was it eliminated like in the Tacoma?

 

Wish I had some good data to add. With just over 1k miles on our new 2021, we towed our travel trailer about 2k miles all over the PNW with zero issues. Would like to have had the dongle to check trans. temps but didn't know about it then.

 

20,000 miles on my 2020 and I tow a enclosed trailer around 3000lbs 5 days a week monitor temperature with scan gauge all the time. Truck is having new transmission installed at dealership as we speak. Completely lost 5th and 6th and right before had very hard up shift along with hard down shifts. Started a case with Toyota and they first said it was a miss build then said it was a mistake on Toyota by mislabeling the window sticker.

 

So what temperatures were you seeing?

Did you tow in D or S4? Tow haul mode?

 

I had a 2008 Land Cruiser and they recommended towing is S4. The Cruiser does not have a tow haul mode. Are you really supposed to tow in Drive with the tow haul mode on? I can't imagine it being good on the trans pulling a heavy trailer in overdrive. Having not studies the manual what is the proper towing procedure?

 

I tow in s4 and temps before trans went out were always between 230 and 240 at the pan and when trans went temps were 260 to 270 at the pan

 

When I’m not towing the average pan temperature will bounce between 210 and 230 depending if I’m on an interstate or a back country road and those temperatures are taken from the pan

 

327Tundra thanks for the info. Sorry that you are going through that with a new truck. What did Toyota mean by a misbuild or a mistake on the sticker. Wondering if your transmission was overfilled as well and the constant higher pressure and wear inside the transmission caused the early failure. Couldn't have been the higher temperature because that is within specs as we all know. Plus you had that stellar Transmission Cooler.....Insert sarcasm here.

 

Welp...I do believe that old familiar refrain, "There have been no transmission failures in 2019+ without the transmission cooler yet!", has just taken a bullet to the earhole.

After two years and 20K miles, and only 3000 pounds TWR, at sunny flat sealevel. But, surely, they say, "It's a bad build, it's coincidence...we need a larger sample of failures to be sure." (Patience...they're coming as the statistical curve allows.)

There are engineers, and there are engineers who do what their boss tells them to do...Like, "SDASTFU".

Sorry, for your pain @327Tundra, but thanks for the real-life report. The silver lining is it did happen under warranty, and you get it fixed on their dime. Ouch.

 

Good morning just wanted to give an update I have been posting about this in another thread also the transmission was filled at the proper level they checked everything for what would’ve caused the failure they do not have a definite answer for why the transmission failed at this time still waiting to hear from Toyota corporate but I have since picked up the truck from the dealership and while driving home with the new transmission minus the transmission cooler temperature reading from the pan is a constant 230 to 235 I appreciate everybody’s concern this is my third tundra never had any problems before but also two previous tundras had the trans coolers

 

Toyota Corporate first stated that Miss build meant in their Termanology that the truck was supposed to be built with the trans cooler then hours later came back and said no it’s not supposed to have a trans cooler that they had deleted it in 2019 and that it was just missed labeled on the window sticker So they advised the dealership and the technician to just install the new transmission

 

If Toyota corporate is smart, they will be all over that "overfilled fluid from the factory" excuse. Forget about failure analysis. They should give you a new transmission, clamp a lid on the failure, and use the singular "human error" excuse. One-time deal...no problem.

They have too many 2019-2021 trucks out there to start retrofitting transmission fluid coolers, or transmissions. Of course, if the transmissions last until the warranty is up; i.e. further out on a statistical curve to be determined...home free with a biga** dent in the reliability rep.

 

Yeah I don’t think we will ever see Toyota just give out coolers. If there did happen to be any sort of recourse we would probably just see Toyota provide extended warranties on the transmission components and call it a day

 

Maybe I could get your input people. I got the Cooler Kit from Nic but haven't installed it yet since I had the shifting issues in my truck and wanted to have it figured out first. My biggest concern is that once you have it installed they won't even look at your transmission to investigate because they will immediately point to the cooler and blame it for any problems you are having related or not- easy out for corporate. Is it worth waiting it out or not?

 

I’d have the dealer at least look at it first if it’s free. Some do charge a diagnostic fee even if you are in the warranty period. It just gets refunded if the issue is covered under warranty.

 

If you aren't doing any towing, waiting won't hurt anything IMO. Indications are normal temperature NOT TOWING is around 220-230 degrees, which should be OK to avoid fluid degradation short-term, but I wouldn't be happy with 230 degrees long-term. JMHO.

Your concern should be if they can't fix your shifting issues, and then fall back on "they're all like that". My understanding is Toyota does not allow them to open transmissions to fix any problems, even they could diagnose them. Your shifting issues will have to be the result of something that can be tweaked from outside the transmission.

Beyond that, transmission replacement is the dealer's only tool. They'll probably start by doing a transmission fluid level check and adjustment if necessary.

 

if transmission temperature stay at 195 as mine does with the aftermarket cooler why not tow in S6? What the advantage of S4. Again if trans temps are under 200F is temperature the only concern?

 

I tow a 6000lb trailer with my 19 and use 5th and towhaul at 60-65 mph unless I'm climbing then I'll shift to 4th or whatever is required. Did the same with my 08 and never had any transmission problems. I did add an external cooler to my 19. I don't imagine there would be problems towing in 6th on fairly level terrain but it does add an extra gear for the truck to be shifting into which I don't like and leads to heat.

 

My understanding is that folks who tow in D or even S5 tend to see more shifting than in S4, especially on hills. I suspect that constantly shifting is hard on the transmission even if your cooler is able to remove all the heat that's generated by that. I'm sure a wiser feller then myself will chime in and correct me if I'm wrong, though.

 

Our trucks come with the 5 year/60k mile drive train warranty. I will do routine maintenance, keep driving and monitor.

 

If you've ever driven a truck that had a transmission failure in yrs gone by you tend to be like WTF why did they remove the external cooler. That's why I added one...pronto.

 

If you study transmission fluid temperatures over a period of time (fluid cooler installed), you will note that fluid temperature actually oscillates between a low temp and high temp. That reflects the normal operation of the transmission thermostat.

For winter ambient temperature in Texas, the retrofitted cooler on my 4.6L runs a range from thermostat "opening" at about 210 degrees (TC outlet), and remaining open until the fluid is cooled to about 183 degrees (TC outlet). The thermostat then "closes" until the cycle starts again.

If you have tow/haul engaged, drive it like the owner manual says. The ECM is going to do the thinking necessary to keep engine/transmission from being overloaded in tow/haul and "D" by selecting the right transmission gear and engine timing for you.

I would not tow in S6. As the operator, you have manually placed the truck in the worst possible condition for towing. You lack the sensor data to make a needed change, and the truck can't change it either.

Transmission fluid temperature is irrelevant to selecting a gear for towing as long as the cooler is doing the job. The transmission fluid cooler's sole purpose is to insure the transmission is supplied with cool oil without degraded properties.

 

I noticed my 2001 Lexus gs300 turns 3000 rpm at 75 mph. Guess if reving to 3krpm hasn't affected its engine life than 3K rpm in S4 or S5 won't affect a Tundra engine life. I will probably tow around 70 mph in S5. I live in Texas and is iscompletely flat, you go less than 70mph and you will get run over. Most are going 80 mph plus.

 

This mirrors my experience as well. About a 20 degree drop in S4 with tow haul on.

 

Thanks for the update.

Those temps look a bit high relative to others experience. Towing in S4 you should be about 15 degrees cooler. This is why I indicated in my other post that a detailed analysis is needed.

Could be a defective cooler (this would suck because your new transmission will get the same treatment)
Could have been defective torque converter clutch or converter itself.
Bearing, shaft, band etc...

 

2000-2002 Toyota Tundra Spec (for ‘drain and fill’) is still quoted (wrongly) at 2.1 quarts.

Actual reality is 4.5 quarts with 20 years experience of mechanics and diy’rs.

Called them last year upon discovery of misnomer. They stand by 2.1.

 

This is just my take...

We don't know to a certainty or even close to that if 327Tundra's failure was from inadequate thermal management (design issue) or a defect (manufacturing) issue.

There is quite a bit of meat left on the analysis bone before I personally would put this incident into the design failure category.

Presence or absence of an aux cooler doesn't guarantee manufacturing defects can't happen that could damage the transmission and generate heat as a symptom.

From another post I made in the Landruiser thread:

I've done post mortem on failed transmissions on other trucks that had internal radiator cooler and aux cooler. The fluid was black, sooty, acrid, and the honest-to-God worst smell I've ever experienced. Same trucks had recent services and were fairly low miles.

Heat generation can happen as failure progresses in a mechanical system. If excess friction exists it will create heat.

For me to get behind these failures as being caused exclusively by inadequate thermal management I would like to see

• Higher failure frequency, with stronger correlation to warmer climates.
• Higher frequency of posts complaining about hitting ATF temp alarm. In other words, lots of folks running up to temp limit of fluid.
• Correlation back to a high failure frequency on 4.6, non towing, units (they didn't have aux cooler either).
• Fluid analysis on failed units showing substantially different properties, particularly high acid number.
• Teardown of hockey puck coolers to ensure that there isn't a defect that is causing lack of cooling. In fact to cover all the bases...ensure there is no cooling system defect like pluggage or loss of coolant.
• (FYI there are/were some fantastic threads on this site on second gen forum of folks diagnosing some strange cooling system behavior that was traced to debris in the system causing a restriction in flow. One was left over parts from a dang radiator cap. Lesson learned--the 5.7 has a failure mode of cooling flow restriction from debris that generates inside the system.)
• Teardown of failed units to find signs of thermal overload on parts
• Teardown of failed units to find the proximate cause of failure--torque converter issue, pump issue, bearing/shaft, clutch/band issue, planetary/sun gear issue, valve body or control solenoid failure (that lead to shifting or lock up out of normal parameters...)
• Overall the failure could be design related or manufacturing related. Differentiating is important.