I just uploaded a series of how to videos on YouTube on how to change the transmission fluid. While I was researching our 6T35 transmission, I discovered that the filter is buried deep in the transmission and the only way to change it is to remove the transmission. Since this is so difficult, it makes sense to change the fluid more often than the recommended 50,000 miles. There is a series of 6 solenoids whose screens would clog if you wait too long and the result is codes and transmission problems.
The procedure is actually very easy and requires simple tools to accomplish. The fluid is Dexron 6 and is readily available at Walmart or any parts store.
The entire process was only about 45 minutes. Mostly due to set up. Next time will probably be about 20 minutes. I plan on doing this every 15k miles. Probably overkill but at $17/gall on, its cheap insurance.
Search YouTube under the title of this post. It’s in 4 parts only because I didn’t want to take the time to string them into 1 video.