Setrab Tranmission Cooler Installed on 2022 Tundra Hybrid

I use my Tundra for a fair amount of towing and trans temps were of concern as the truck lacked a conventional trans cooler compared to my previous trucks I've owned. After logging data with an OBD scan tool I found that the minimum operation temp of the transmission in normal(no load) driving was around 190F. Loaded or towing this number would climb to 220-230 quickly and seem to hand out around there. I began by pinning the thermostat open on the trans which lowered unloaded temps to 150-170 in normal driving but, I still hit 220-230 when towing around 6K LB on flat interstate. I had concern as most of my hauls are only 1 hour or less that if I needed to haul an hour or more that high temps would become an issue, especially on hilly terrain. Toyota seems to believe these temps are ok but, everyone seems to complain about the lack of capability and trans overheating while towing or off roading. I love the truck and hybrid powertrain, to me the torque and towing power are incredible and far superior to offering of other manufacturers. I just needed to address what I felt was a lack of duty cycle for the transmission. I will share my solution and hopefully benefit other members who may be considering doing the same. I will refrain from any debate of whether its needed as that decision is ultimately to the owner and what they feel best.

Cooler: Setrab 50-920-7612
Mount Kit: Setrab 23-9002
Port Adapter: 22-M22M14 Bushing
Fitting Adapter: M14 X 1.5 to 10MM Barb 90 Degree
Hose Connection: 3/8 Brass Barb Hose Splicer
Misc hardware: 2" Aluminum Angle
Hose: 3/8 Trans Cooler Line US Made 25FT
Hose Protection: 1/2 Braided Sleeve
Cooler Fill: Lubeguard Platinum 15oz

I mounted it in front of the radiator using the core support an upper anchor point and hood release support as a lower mounting point. The pictures should properly illustrate this, if you have questions ask, and I will do my best to clarify. Essentially this cooler slides in from the top between the front grill mounts so all your work is done from the top. You must be mindful of the shutter on the front and not mount too closely to it to block operation. You must also leave enough clearance on you upper mounts to put fittings and route hoses. I tied into the line coming out the factroy "cooler/warmer" on the return side and plumbed this cooler in the middle. It takes the fluid on the return path from the factory system and cools it prior to going back into the trans. I will share results and testing in subsequent posts to this thread.

 

added pic

 

added pic

 

added pic

 

added pic

 

Results so far are as follows in about 60F ambient with the factory trans thermostat pinned open.

Unloaded driving after 1 hour on the interstate @ approx 80MPH, 138F peak
Stop and go traffic with little to no airflow over the cooler, 167F peak

 

just curious, where are you getting this from, I don't seem to recall anyone saying that or having a trans overheat?

anyway, glad you worked it out if this is what you feel your rig needs

 

Nice. Planning on doing the same to my truck

 

Great job and nice write up. Curious why the temps need to be sub 180° when that is right in the middle of the operating temp. WS fluid is fine at 230°. I would keep the cooler and unpin the thermostat if it were my rig to get the fluid up to temp quicker and keep it in the optimal range.

 

No idea why you would leave it pinned open. Just the let the cooler do its job and I bet you are +/- 5 degrees going from the lightest possible load to towing a 10000 lb trailer up a mountain. Now no load driving will be 190 and towing will be 195, 200 at most. Those are perfectly reasonable numbers and your transmission wont be perpetually cold.

 

Story of every Toyota truck sold in america.

 

probably a sensor error seeing how this new rig behaves, lol.

 

No no no no no...

 

Balderdash, I says.

I'll not stop my tireless efforts to develop the Spraynard Heavy Industries mast-mounted, radial array transmission cooler until ATF temps get so low that it assumes the properties of a super fluid such as Helium-3.

 

Even nitrogen will turn to liquid at those temps. Liquid equals lube

 

This. Low temp ATF fluid is as much a danger to your transmission as fluid that is overheating. ATF's proper operating temp is generally between 190-235F. It can vary based on your location, elevation, and usage. You don't need to start worrying about temps until they get above 240F.

If OP is driving around with their ATF at 167, its not warming up properly and not properly lubricating the transmission or evaporating any water that may have accumulated. This is a failure waiting to happen.

 

I have towed a 6K LB trailer with the thermostat pinned open(no auxillary cooler) and hit 230F in one hour on flat interstate, more weight or elevation will bring you to that temp faster. Even after emptying that load and towing and empty trailer the transmisson would not shed the heat on the one hour return ride. In winter I may use the the thermostat by unpinning it, for now I want to see what I peak out at towing heavy with it bypassed. I am of the opinion there is a thermal capacity issue in the existing system that it will overtemp at loads well under the trucks rating. Time will tell if this cooler is sufficent to keep temps under 225F towing 6K plus for exteneded periods(1 hour or more), if so I will test with thermostat operating. I will continue to share data as it becomes available.

FWIW, running with it pinned will and no auxillary cooler temps unloaded were in the 150-170F range and get there pretty quickly, probably 5-10 minutes of driving. For those considering pinning only and possibly towing a boat this is what you're working with. Proabably one hour on flat ground on the interstate before you get over 225F.

 

Does anyone know the exact temps the trans thermostat open/close?

 

Or you could just try it unpinned and leave it like that year round when it works. Leaving it pinned doesnt change the cooling capacity of the system, it just lowers your normal daily driving temperature. You said yourself if sits a 138 on the freeway pinned.

My Lexus GX would get up to 250 with the stock cooling system. All I did was add a hayden cooler and now it wont break 200. But it also stays above 190. So it basically just operates within a 10 degree range whether im running to get groceries in the winter or towing my 5500 lb travel trailer over a 9000' pass on a 90 degree day in the summer.

My F150 operates the exact same way with a factory external air cooler. It will hang around 200F unloaded due to the thermostat, but in the 20000 miles of towing my travel trailer in Utah and the surrounding states I have only see it over 210 once or twice.

 

No no no no no...

 

That better not mean what I think it does.

 

Hopefully Ratio Tek can make a shift kit for these transmissions.

I installed one in my A10 Mustang transmission, it stay at 192. If I beat on it it’ll creep to around 205. Really nice kit, increases the clamping force of the torque converter and enhances the lubrication capabilities of the transmission.

anyhow I don’t like how hot this transmission runs. I agree with Mass-hole. There is that sweet spot also. Like Goldilocks said it can’t be too hot or too cold.

 

I wouldn't like those 230 ATF temps either. TFL guys think it’s high also.

https://tfltruck.com/2021/12/transm...-go-up-the-worlds-toughest-towing-test-again/

 

Well, bless your heart!

 

@KFRC46
Any updates how your transmission has been running with your setup and current hot weather?

I for one do not like how hot this tranny gets, I’ve been monitoring my temp with this current heat wave, it has gotten up to 235 then slowly creeping back down to about 219.

I would eventually like to do your setup. Do you have any more pics, how the plumbing looks at the transmission side?

I’m surprised more forum members are not concerned for the longevity of their transmission….

 

Ignorance is bliss… SR owner here. No trans temp gauge. Wish there was one even with after market.. I do tow so it would be nice to see how hot that oil gets

 

How do you pin the stat open?

 

This has been an "issue" for a long time with Toyota's and I really havent seen many transmission failures.

If I were you, just get a

$53 Hayden 678 Universal Rapid-Cool 9.5” x 11” Add-On Transmission Cooler – Not for Direct Replacement of the OE Cooler

Hayden 678 or similar. They are like $45 on Amazon and should give you a significant amount of cooling capacity.

 

Thanks for that info Mass-hole. I will pick up one of those kits. Just want to see want the procedure/ plumbing looks like.

I really wish Ratio Tek made a kit for these transmissions.

I installed one of their kits on my A10 Mustang, temps stay at a consistent 192, if I beat on it it’ll creep to about 205 max. Very awesome kit.

Does anyone know the Aisin transmission model number ? I want to see if I can find a suitable.

 

What does the A10 mustang use for a cooler? The A10 F150's have a big liquid/oil cooler underneath the truck near the bellhousing. Coolant is pumped back to the cooler. The trans fluid no longer gets pumped up to the radiator like on the trucks prior to 2018 so it makes it harder to add an air cooler. You would have to splice into one of the relatively short cooler lines and run it all the way up to the front.