I've got an '05 screw, 5.4, automatic that plainly says mercon v on the dipstick. However, the mechanic that changed the filter has put in dexron ll . How long do I have to get it back to the shop and changed out. Thanks

 

Why did it even leave the shop?

Regardless, change it out as soon as you can. Obviously, it's driveable, but don't tarry.

And find a new mechanic.

 

Why are you asking when you know it's wrong?
You drove away, just drive back.
If the pan only was down and no converter drain was done then the two fluids are mixed at about a 40/60 ratio.
You need a full flush now to be sure the mix is removed. Any shop shop should be able to do this now.
If you have warrenty you better get this done and go to a different shop that knows better.
Sorry to get on you case a little but!!

For me, I have a custom rebuild heavy duty that no longer uses Mercon V fluid so I have to be sure to tell anyone who changes it what to put in.

 

I'm asking because I figured it was wrong and don't have the knowledge that I know is out there. It was driven away because my wife took the truck to the shop, picked it up, and drove it home yesterday. I found out last night when I was looking at the reciept. Thanks for your help.

 

That fluid is missing a friction modifier that the 4R70w and 4R75e requires to last.

Adrianspeeder

 

If it was a pan drop, filter replace, and refill I would'nt worry at all. That only replaces 4 out of 14 quarts. My local dealer uses regular Mercon on all simple services. Mercon V is used on flushes. These transmissions originally ran on Mercon, it won't hurt a thing. That said, Mercon V is superior as is a synthetic fluid. On your next service just ask they use and request Mercon V if need be.

 

The 4R70w used Mercon from 94 till 98ish when ford figured out that friction modifiers were needed to keep it from burning up. Hence the Mercon V requirement.

Adrianspeeder