I think few would argue against regular trans fluid changes - myself included. The arguments for doing so are many and compelling.
The arguement for NOT doing it relates to high-mileage units with little or no previous maint. Or any evidence of any previous maint. Then it's a crap-shoot.
There are far too many examples of folk with trans unit functioning ok or with only minor issues who then proceed with a full fluid flush, using advise offered with the best of intentions, only to have a full trans failure very soon afterwards... Bugger....
It seems that if you don't get it young, and establish a routine of regular changes, then you run the risk of shocking an older unmaintained unit by introducing new fluids, dissolving the build up of sludge already in the unit.
While not usually fatal, as a mechatronic replacement or rebuild will often address the resulting failure, it seems few folk have the stomach for this level of work.
Einy meeny miny mo.....
