I know Mercon V has been approved for a long time now. So has most everyone finally agree that Mercon V is "safe" or not. At the beginning some stated Mercon V didn't work for them. I think Ford changed Mercon V a little bit to ease those concerns. So basically who refuses to switch? I am still using Mercon and will be doing a transmission fluid change again in 6k miles. Just getting ready to buy fluid again and like the current state of this debate.

 

To me there was never a debate. Ford issued a TSB to stop using Mercon and to start using Mercon V in all applications. Doesn't sound like much of a debate to me.

 

Well there were those who refused to change because it happened to them or someone else that the Mercon V trashed their 4R100. Other sites have those who say it's safe and those who said it was the devil. So there were for sure those who would for sure disagree on the matter.

 

It's more likely that their 4R100 trannys had issues to begin with and the fluid/filter change was the final straw that killed it. Using Mercon V instead of Mercon was just some convenient place to lay the blame. Those same trannys could've failed just as easily had the change been done with straight Mercon. There is just no way to know for sure. But if there was only 1 failure for every 100,000 successful fluid changeovers, then I'd say the numbers favor using Mercon V.

 

in short:

yes, the debate has been settled.


i also asked mark K. directly.
https://www.ford-trucks.com/forums/1...l#post13635046

IMO, there should be no debate.

 

Post #18 and #19 seems interesting. I have always read (older post granted) to never mix the two together. Now it seems okay to do so. I do not plan on mixing if i go mercon V , i know a little will mix when changing out myself. So i am feeling better about it.

 

The only problem i have with this that thought is when the playstation 3 would do a software update. Some people bricked their PS3 when installing the update. Sony wouldn't admit fault or warranty the console. I do think enough time has passed to be okay switching fluid. Is there enough advantages to switching even with a 30k change interval?

 

i think the advantage is with Mercon V you can buy a fluid which has been tested and approved by Ford.

whereas, with Mercon, you cannot.

that is to say, you know Mercon V is the right stuff if the bottle has the Ford approval number on it. Mercon is no longer being tested by Ford, so you have to trust the manufacturer when it says it is the right stuff and is compatible.

now, whether the Ford certification means much to you or not is up to you.

 

As I understand it, the ones that got "bricked" were the ones that had been hacked or modified in some way.