Prospeeder

I totally agree is unnecessary. But its not as if they flush and kick up debris. Its just a passive, old fluid fills up one tank, new fluid is pulled into the transmission until clean fluid is coming back out. Iv yet to see anything bad happen. When people go to have a service when the transmission is acting up, and it doesn't fix it, or it fails, its in no way the new fluids fault, the transmission had a problem, it was going to fail. Its called preventative maintenance, not wait till its messed up and then try to change fluids.

Adjuster

My thought is, would you change your engine oil, but not the filter?

I would not do the same to the transmission. It's true the existing fluid can become burned, and oxidize, but flushing out that fluid, while leaving the filter dirty, is just a short term fix, if it works at all.

Now, if you have zero problems with your transmisison, and you flush out the old fluid, and replace it with new to maintain the quality of the oil?

That's not a bad idea.

The Frenchy

Hello,

I do this job last week end.
Everything was perfect, change 6liters of ATF fluid, and oil filter inside.
New join too.
It take me 5 hours, quietly, to unmount, to clean and refilling.
All is OK now.
Just an information for you, this special oil was used in Audi, BMW and Peugeot. The Peugeot price is 50% off.... Here in France. (18 euros Audi and 12 euros Peugeot, this for one liter)

Have a nice day.