Transmission?
Senior Member
Joined: Sep 2004
Posts: 3,115
Likes: 0
From: Winnipeg, Manitoba
...that is the question...this guy's logic seemed sound to me...that a trans is a closed system, unlike engine oil that breaks down and gets tainted by gas/diesel.
Is this way off base? The idea that the trans fluid shouldn't really get "dirty" unless there is a problem with your trans? That the trans won't suffer from cycling in 5-6 q of new oil periodically and reaping the benefits of saving the $100+ for a flush? I'm sure there have been a few "auto treatments" that have been created more for the purposes of making money than for practicality...
Is this way off base? The idea that the trans fluid shouldn't really get "dirty" unless there is a problem with your trans? That the trans won't suffer from cycling in 5-6 q of new oil periodically and reaping the benefits of saving the $100+ for a flush? I'm sure there have been a few "auto treatments" that have been created more for the purposes of making money than for practicality...
Besides, $100 every couple years or $2000 to replace/rebuild the tranny. Which would you rather spend?
Senior Member
Joined: Sep 2004
Posts: 3,115
Likes: 0
From: Winnipeg, Manitoba
The Ford filter is nothing more then a screen, not every tranny is the same. The aftermarket filter that went into my tranny at it's last service is fine enough to properly filter the fluid.
Junior Member
Joined: Jul 2009
Posts: 3
Likes: 0
From: Fredericksburg, VA
Appreciate it...
Thanks, Tbird, for your input. Like you said, a tranny flush is only a $100 or so every couple of years- I want my truck to be around for a LONG time so I don't mind investing a little back into it every now and then...it's almost paid off! 
Senior Member
Joined: Apr 2006
Posts: 521
Likes: 7
From: Sacramento, CA
Flushes on a older tranny could be death. The particles are driven into the valve body and then you are toast. A fluid exhange using the Tranny pump is ok, Dropping the pan and changing filter is good...Change fluid a couple of times and it will look pristine.