Hi Scotty!
Thanks for being such a great person! I appreciate all you do for us regarding our auto related needs!
I recently purchased a 2019 Toyota Tundra with about 35,000 miles. It is the 1794 trim edition with the 5.7 V8. I found out that Toyota stopped putting the transmission cooler on the Tundra for the 2019, 2020, and 2021 model years. There is much controversy in the owner community over this change. There are several videos on YouTube with various opinions on the issue. Several owners have measured the temperatures of the Tundra transmission without the cooler and have seen temperatures as high as 245 degrees Fahrenheit. Older year Tundra's with the cooler don't get much above 200 degrees even when towing.
When asked, Toyota engineers state that the higher operating temperatures without the cooler are within the "operating range" of the transmission and acceptable, so they say why have the part if you don't need it. Toyota also says the transmission warmer doubles as a transmission cooler. (really??)
My questions are as follows: Why would Toyota take the cooler out of the exact same model truck? Should I be concerned about the dramatically higher temperatures of the transmission operating with the cooler? Would it be wise or even necessary for me to retro fit my Tundra with the transmission thermostat and cooler? (older model thermostat and cooler parts bolt in the same spots with little to no trouble) What is the honest answer about the acceptable operating temperatures with a truck transmission?
Thank you so much for your help!
Anthony M
@articfire
yes, just like an engine, the transmission has an optimal operating temperature range, which is not too cold.
The answer is simple: to save cost. In general automotive engineers push the mechanical limits of parts pretty close to their max. It is believed that this is because they will get more money licensing replacement parts when the parts go bad (but this is just a broad theory that mechanics share). There is NO downside to adding a transmission cooler other than the potential maintenance cost of it wearing out. Its settled science that heat is the primary source of wear in both engines and transmissions. This is especially true for automatic transmissions which rely on a robust and some-what complex sealing system. If you do a lot of towing - ADD THE COOLER. Its desirable, most manufacturers have them standard on their truck lines that are marketed for towing, and those who do not have one and do a lot of towing always wish after the fact that they had added one.
That was the question I was going to ask when I came here, searched for it, found it, and the answer is what I suspected. I hit temps of 212 on flat roads, with no load, driving around 65mph when my Tundra was new. Had a cooler put on at 200 miles, glad I did.
Well, especially if you do any towing it is a no brainer. A transmission cooler can be had for around $50, and they are easy to install. I bought a hayden for my 4runner years ago and it did great.
My GX470 has a small one, I am tempted to upgrade to a bigger one though as I tow. I use a scangauge II to monitor transmission fluid temps and water temp. Even while towing in hot weather, I don't think I go over about 205, most of the time around 190.
