No they aren't but, put Dexron in a Ford transmission that requires type F and see what happens.
Don't keep us in suspense.
They become a slush box. It's been my experience after 45 years in this business that in some cases choosing the wrong fluid for your transmission can indeed destroy it. Many fluids don't mix well and quite frankly since the OP is discussing a stock transmission where all the fluid can not be removed the only safe answer here is to replace the fluid with approved fluid. Now if you are building a high performance transmission with all new frictions and a converter where all the fluid is going to be replaced then starting out with type F is OK, but just replacing half the fluid with type F isn't the best advice in my opinion.
So, tell us, in technical terms how a Ford transmission differs from a GM or Mopar. Is the friction material compounded differently? Are the bearings and bushings way different?
I totally agree on the difference in lubricity and coefficient of friction differences and that type F is a bandaid to patch a flawed design but in many cases the more aggressive friction characteristics are desirable and the slight difference in lubricity isn't really a factor. Manufacturer's specs for fluid, in most cases is simply a matter of "made here"...IOW, if it isn't made here it spells disaster, kinda like your Mopar dealer chanting "use only genuine Mopar parts in your new Dodge".
In newer transmissions with overdrive and lockup converters, fluid choice is a lot more critical than in the old transmissions most often discussed here. Look at how many here have had success with John Deere tractor fluid and AW-32 hydraulic fluid. Are their anecdotal stories of success any more/less credible than your anecdotal story of failures associated with the wrong fluid and, most likely, lacking laboratory failure analysis?
