2019 2020 transmission cooler missing

Funny....I bet lawyers can argue you bankrupt about the cooler, but I've never found my tranny temp gauge.

 

Yup - that’s a fair point. Even the SR comes with it.

 

Could you send a sample of fresh WS fluid to blackstone or another lab and get them to tell you the temp at which it starts to break down?

 

These are my temps (2012) with mishimoto thermostat, new rad hoses, fresh coolant, drain and filled with amsoil atf a few times over the years and the cooler pinned opened. Unloaded, 90F weather, hour or so of driving.
Loaded (500+ pds) coolant temps no higher than 190, trans temp no higher than 190.

 

I can’t find the Trans temp gauge on my 2019 SR either...maybe they added it on the 2020s?

If we put our common sense hat on, and ask simply “why did the Toyota engineers redesign the external cooler for the 2019+ model year?” I don’t know the answer, but I don’t think it was just to remove cost. Especially on an aging Powertrain platform like the Tundra. The answer to that question would be very interesting to hear.

 

I have a 2020 SR5 with tow package. There is no trans temp gauge that displays on the DIC that I have found

 

So you are running the 160 degree thermostat and have no issues ? No check engine light ?

 

This is correct.

Other OEM forum folks have had success dropping trans temps doing some combo of increasing rear gear ratio and also lowering thermostat temp. Combining both really knocks down the temps.

However in tracing the routing on the coolant lines to the existing warmer/cooler, it gets coolant flow from the heater core outlet.

I'm building a parts list now to try to put a large heater core in line between heater core and trans cooler to drop coolant temps further.

 

I'm gonna beat my chest on this one. 1st point, I'm a ASE Master Tech. 2nd point, I'm a Lemon Law Arbitrator. 3rd I'm a Technical Expert for my state. I've been in the automotive industry my entire life, I've worked with and against a great deal of the manufactures and proven using their data when a vehicle has a malfunction or when it has been consumer misuse and or abuse. I know the Magnuson-Moss act forward and backward (especially on modifications), I can almost recite the Lemon Law in my sleep (ask my girlfriend) I'm not worried. I'd bury Toyota on this just based on the window sticker, their own WS fluid max temp rating and the data that comes from their own CAN system that monitors, reports and records their data from their vehicle. There will NOT be a RECALL, this is not a safety issue. There may be a TSB or a customer support settlement (5.4L 3V Spark Plug Breaking in the Heads) for a cooler. Toyota knows they have a problem but the problem is likely less than 5% of the trucks sold. Keep your fingers crossed for a TSB or Cowboy up and buy a cooler kit from @chasenicholas93 and be done. The only way to screw up the install is to not add the addition 1.5-2 quarts of fluid, then it's on you. End rant, please leave me alone unless you have a failure that has been denied and are ready to make legal precedent.

P.S. I'm not Pro Bono.

 

One thing to consider here with dropping temps too low or perhaps a technical reason to keep temps elevated...

If it is the case ( I think there is alot of evidence it is) that the WS has some composition with a non trivial amount of polyol ester lube, then the trans fluid could absorb a whole lot more atmospheric moisture than a regular mineral oil based transmission fluid.

So keeping temps really low like below 190 for long periods could over time create a moisture issue unless the fluid is changed.

 

Great information for sure. I came from a Tacoma. I had an 07 TRD sport. Because that was out of warranty when I first bought the truck at 68000 Miles about 10 years ago I put red line fluids in the differential, transfer case, and transmission. That's probably what I will do to the tundra when I install a transmission cooler. But for warranty purposes at the moment I'm leaving the WS in

 

WS fluid has been running in this transmission for the last eleven years at around 190F and hasn't had a problem with moisture.

 

A customer concern settlement is what I am looking for. Especially with the data that I have backed up. With only more Rock Solid data coming in. As you stated, I do plan to add a cooler to my Tundra. But is it also true that you should never mount a transmission cooler with the inlet and Outlet lines facing down? On top of that, is there an inlet and outlet flow on the "warmer" ? I feel like that is very imperative to when installing a cooler as well

 

190 and above yeah is likely ok. When driving or towing there is likely a good amount of time for fluid to reach 200-212 F and release absorbed moisture.

 

Yes, inlet and outlet should NOT be on the bottom. Outlet must be on the top of the exchanger.

Flow direction through exchanger can be specific, but it is unlikely for a simple transmission cooler. Follow manufacturers directions if any. If the flow direction is important, the connections will stamped "inlet" and "outlet".

Edit: To retrofit an external cooler, you'll have to add the thermostat.

 

How to Monitor Temps: Cheapest option is to buy the app "OBD Fusion" on your phone and input the custom PIDs for the pan and torque converter temperatures (see below). You will also need the bluetooth OBD adapter. There are many brands but here is one of the cheaper options.




$33 Veepeak OBDCheck BLE OBD2 Bluetooth Scanner Auto OBD II Diagnostic Scan Tool for iOS & Android, Bluetooth 4.0 Car Check Engine Light Code Reader Supports Torque, OBD Fusion app
https://www.amazon.com/Veepeak-OBDCheck-Bluetooth-Diagnostic-Supports/dp/B073XKQQQW

In order to input the pan and torque converter custom PIDs on your OBDFusion app go to "settings" then "User-Defined PIDs". Copy the information below. Leave everything the same besides what I am telling you to change.

ATF Pan
Name: ATF Pan
Description: ATF Pan
English Units: F
Min Value: 0
Max Value: 300
OBD Mode: 21
PID Number: 82
Equation: ((((A*256)+B)*(7/100)-400)/10)

Torque Converter
Name: Torque Converter
Description: Torque Converter
English Units: F
Min Value: 0
Max Value: 300
OBD Mode: 21
PID Number: 82
Equation: ((((C*256)+D)*(7/100)-400)/10)

 

No issues so far. 5,000 miles on it. Was going through the mountains last night. Outside temps were 50F. Average temps = Coolant -170, trans- 170. Running smooth. No CELS.

 

On the phone with Toyota now. Gonna see what they wanna do about this.

 

Just got off the phone with Toyota, they stated this needs to be taken up with the dealer and they will have the dealer rep call me to discuss.

 

And if Exxon told you that their fluid decomposes at, say 280 degF, next week Shell will be advertising that their fluid decomposes at 290 and steal a bunch of Exxon's customers.

Just because they WON'T tell you something doesn't mean they CAN'T.

 

Need to put the superscript "tm" after Rock Solid.

 

Mobil site seems to be down lol...I think we broke it.

 

How were you able to find this info when the OP wasn't?

 

someone was able to locate it in the TIS system. The transmission fluid max temp is 221 degrees.

 

2018 and older Tundras have a running temp of around 180 to 185 not towing.

 

My 2020 is running 225 to 235 not towing.

 

It gets plenty hot down here in GA... so I just ordered a 160 degree T-stat.

I will be adding the transmission cooler also (waiting on parts to arrive)... so hopefully things will stay nice and cool over the long term.

 

It's not in the TIS system and have no idea why the 221F keeps coming up. The OP said he was contacted by Toyota through TIS. I asked him how that was possible and he then said a customer rep told him it was in TIS and mentioned the 221f spec. There is nothing published by Toyota in TIS that mentions specifications of WS fluid.