Installed a transmission cooler on my 2021 Tundra TRD Pro. Here are the results.

Hello friends!

I discovered this last summer after towing a 7,000+ camping trailer with my 2021 Tundra TRD Pro in flat ass Texas with no hills just kiddos, wife, and trailer, I was averaging 235-248 degrees in my transmission. Even with normal driving with just me in the truck I was averaging about 205 degrees for my transmission fluid.

So, I went and bought the Genuine Cooling Systems transmission cooler and had it installed. I am happy to report that with normal driving I am averaging around 185-190 degrees, and that same camper with the family in tow, over labor day weekend I never got above 215-218 degrees.

I want to take a second to say on behalf of all 2019-2021 Tundra owners and say, "F**k you Toyota. F**k you for taking the transmission coolers off of these trucks and putting us in this position of burning up these amazing AISIN transmissions prematurely!"

The fact they have the Gaul to say you don't need one, and that we should be changing the fluid at 100,000 miles is an absolute SPIT in the face of us owners.

I had the shop that put the cooler on change the fluid while they were at it, and it was dark. My truck is at 65,000 miles, and I don't tow much at all maybe 2-3 times a year (that camper by the way which is owned by my parents), and the shop said the transmission fluid had no chance of making it to 100,000 miles.

On top of this and the fact 2022-2025 Tundra's have faulty engines has all but made me never want to own another Toyota product again.

Ok, I am stepping off my soap box.

Gentlemen, if you own a 2019-2021 Tundra the cooler I think is an absolute must own. Do not wait until 100,000 miles to change your transmission fluid do it at the 50,000 mile mark. Don't believe a dang word coming out of the mouths of Toyota they don't care about us anymore.

Here is the link for those that want to get the cooler. https://genuinecoolingsystems.com/

 

You just have to own an OLD toyota, everyone should boycott the new ones until toyota pulls their head out of their rears.

 

I agree the cooler is a good idea, and I run one too. In case you’re not aware, Toyota WS fluid turns dark pretty quickly with use, so color isn’t a great indicator of fluid condition. Hopefully you got it before damage was done. Did they mention any other issues with the fluid?

 

Just curious but we're you im S4 and tow haul mode when you saw the high tranny temps?

I agree its probably the best longevity mod to do.

 

Great question. Tow haul mode and then do tap shift. If I am flat I will run in 5th gear at 70 mph but depending on the load stay in 4th gear. The goal for me is to maintain 3,000-3,500 RPM to stay at the max power band. The high temps were regardless of the gear. They were just always high which I find disturbing.

 

Great question! They did the white paper towel test. They poured some of my fluid on the paper towel next to good fluid, and mine was orange. They said if was still pink'ish it would be fine, but they said orange you replace so I did. I looked it up after and confirmed that they were right.

 

Like the other poster said it turns dark quickly. Im not saying you shouldn't have changed your fluid. Keep changing it and the cooler will help. But in 5k miles mine turns dark and looks bad like it has 100k miles on it on paper towel next to new fluid.

 

I just put a must have cooler on a 2021 and the color on the paper towel was blue wow? I went with a 28 row G-plus stock hard lines from 2018 shock all the rest and i could not be more happy ! cost me 600 & some time but I can now drive / tow an not worry at all worth every penny !!!

 

Glad I have the parts coming. Couple weeks back I did a drain and refill at 54k miles on my '21. Fluid was darker than I'd like to have seen but based on this thread, perhaps it's expected. Regardless, I won't wait another 50k to do another drain and refill.