From my inbox:
"My name is Mario D. from San Antonio, TX. I just finished reading your article on Victor Sheppard's 2nd million mile Tundra. Interesting read. My father has an 07 Tundra (5.7) with just over 100k. He's torn on whether or not he should service the transmission (drain and fill). He's talked to some Toyota service techs that say there's no need as they are "sealed", while he's heard from other mechanics every transmission needs servicing. My question to you is, and I understand it might be a long shot, but would you mind reaching out to Victor and asking him if he would service his transmissions? Or did he leave it untouched?"
My response:
The short answer is: once at 700k miles when the transmission acted up.
The long answer is you are going to get a lot of different opinions on this topic. Why? Things have changed so quickly for oils, service departments don't always keep up.
Over the years, we've seen lots of changes with regards to oil. For example, synthetic oils have now become the oil of choice. When I was growing up in the late 1990s, synthetics were new and most people didn't understand them. You'd go to the dealer and get offered multiple choices of oil. Now, we are using super lightweight oil with much higher wear resistance and longer life than ever imagined back then.
The same is true for transmission oil. It is now synthetic and is rated to last the life of the transmission. It isn't "sealed" per se, you can still access it, but there's no longer a dipstick because you don't need to check it. Some owners hate that answer and will check their transmission oil and flush it regularly. Some Service departments will do the same thing relying on the "what we always done" approach. I found one service department that recommended a transmission fluid flush at 30,000 miles. That's some old school thinking.
Finally, one more example on how fast things change. A few years ago, Toyota did away with the transmission cooler on the 2019 Tundra and Sequoia. Why? An engineer looked at the temperatures the transmission was hitting and realized, they didn't need the cooler. Synthetic transmission fluid can regularly run in the 200 degree range and even higher without breaking down. Toyota designed the Tundra back in 2013 and just in the course of 6 years, they discovered they didn't need it. Interestingly enough, the 2024 Tacoma and 2022 Tundra (the new one) both have transmission coolers. The engineers tell me that's more to do with the heat created by the turbocharged engines than the transmission.
For me, it all comes down to several factors:
1. How do you use your truck? Towing all the time? Live in a cold climate with temperatures below freezing and hauling or towing stuff?
2. How new is the truck? If you have a truck built in the past decade, you shouldn't worry about the transmission like the older trucks.
3. What oil came with the truck? If it is from factory, it has synthetic.
You'll find the 2-3 min section of this video helpful:
"My name is Mario D. from San Antonio, TX. I just finished reading your article on Victor Sheppard's 2nd million mile Tundra. Interesting read. My father has an 07 Tundra (5.7) with just over 100k. He's torn on whether or not he should service the transmission (drain and fill). He's talked to some Toyota service techs that say there's no need as they are "sealed", while he's heard from other mechanics every transmission needs servicing. My question to you is, and I understand it might be a long shot, but would you mind reaching out to Victor and asking him if he would service his transmissions? Or did he leave it untouched?"
My response:
The short answer is: once at 700k miles when the transmission acted up.
The long answer is you are going to get a lot of different opinions on this topic. Why? Things have changed so quickly for oils, service departments don't always keep up.
Over the years, we've seen lots of changes with regards to oil. For example, synthetic oils have now become the oil of choice. When I was growing up in the late 1990s, synthetics were new and most people didn't understand them. You'd go to the dealer and get offered multiple choices of oil. Now, we are using super lightweight oil with much higher wear resistance and longer life than ever imagined back then.
The same is true for transmission oil. It is now synthetic and is rated to last the life of the transmission. It isn't "sealed" per se, you can still access it, but there's no longer a dipstick because you don't need to check it. Some owners hate that answer and will check their transmission oil and flush it regularly. Some Service departments will do the same thing relying on the "what we always done" approach. I found one service department that recommended a transmission fluid flush at 30,000 miles. That's some old school thinking.
Finally, one more example on how fast things change. A few years ago, Toyota did away with the transmission cooler on the 2019 Tundra and Sequoia. Why? An engineer looked at the temperatures the transmission was hitting and realized, they didn't need the cooler. Synthetic transmission fluid can regularly run in the 200 degree range and even higher without breaking down. Toyota designed the Tundra back in 2013 and just in the course of 6 years, they discovered they didn't need it. Interestingly enough, the 2024 Tacoma and 2022 Tundra (the new one) both have transmission coolers. The engineers tell me that's more to do with the heat created by the turbocharged engines than the transmission.
For me, it all comes down to several factors:
1. How do you use your truck? Towing all the time? Live in a cold climate with temperatures below freezing and hauling or towing stuff?
2. How new is the truck? If you have a truck built in the past decade, you shouldn't worry about the transmission like the older trucks.
3. What oil came with the truck? If it is from factory, it has synthetic.
You'll find the 2-3 min section of this video helpful:
