808muscle

Absolutely. If you race your vehicle or drive your vehicle that would cause the trans fluid to get very hot, over time it breaks the fluid down. Its not a huge job to drop the pan and swap the filter. Pumping the fluid back in is messy and kinda of a pain since your laying on your back all twisted up while working the hand pump. The important thing is too make sure the car is level otherwise the fluid does not go back in properly.
I change mine every year since I race so much.

stealth_GT

Hell yeah.. about as important than your regular oil change.

Working at a shop last year, I did a few filter changes.. the fluid that comes out is pretty nasty.

Nuke

Be aware that simply dropping the pan on an auto only releases a minor amount of the total tranny fluid volume. The only way to do a complete exchange is with a power flush.

allinon72

Correct, but if you drop the pan at reasonable intervals, say every 40k, it will keep everything working properly without disturbing any potential buildup in the tranny.

Derf00

I've had my wife's Escape power flushed at 60K and the stang at 30K..flushed as in they push fluid through the system in the opposite direction until it comes out clean.

ZERO problems.

the longer you wait to do this the more likely you will have major deposits and sludge that will come loose when you have it performed. Just like regular oil, wait long enough and there will be sludge. A drain and refill really does nothing since about 50 to 60% of your fluid is in the torque converter, tranny lines, and tranny cooler.

SCCAGT

These two posts say it all. However, a drain and fill DOES do something. You are replenishing over half of the fluid. That new fluid has a fresh level of its additive package in it to continue doing the job of keeping the transmission free of nasty build up. No, its not as good as a flush. But its certainly far better than nothing at all.
Its cheap maintenance.

However, every flush machine I know of, mine included, does NOT reverse the flow of the fluid. They cant. The machine uses the pressure AND DIRECTION the fluid flows from the transmission. The machines themselves dont generate pressure. Both of those conditions would be detrimental to the transmission because the engine has to be running in order to flush the transmission. The transmission uses that energy to rotate its own pump in order to circulate the fluid through the flush machine. Without the engine running, it is impossible to flush.