Whats the right Tranny fluid?

[LPstroker]

I got Penzoil ATF, on the front it says "For us in vehicle previously serviceable by DEXTRON-III/Mercon Brands". I have an 03 7.3L 4X4 Auto.

[melmount]

I think Mercon V

[LPstroker]

On the dipstick it just says use mercon.

[NYMustang50]

Ford released a tsb saying that all transmissions that use mercon can now use mercon v. Mercon is being discontinued and is not in production anymore. But since you already have that atf you stated that will be fine as well. The tsb was dated in some time in 07..

[LPstroker]

Originally Posted by NYMustang50

Ford released a tsb saying that all transmissions that use mercon can now use mercon v. Mercon is being discontinued and is not in production anymore. But since you already have that atf you stated that will be fine as well. The tsb was dated in some time in 07..

So the stuff I have it wont damage anything? but in the future I should use Mercon V. Thanks.

[melmount]

I think mercon v is synthetic and mercon is not? I could be wrong, i am sure someone will chime in here...

[alabamafrog]

Make sure you got enough, it takes around 17 Qts to change mine. I use the Ford brand Mercon V cause that’s what came in it and I don’t like mixing fluids. I change mine every 30-40K miles.

[NVJAY775]

Kind of a pain to flush first, but I use AmsOil Synthetic.

[NYMustang50]

Originally Posted by melmount

I think mercon v is synthetic and mercon is not? I could be wrong, i am sure someone will chime in here...

Its kinda not there was a big lawsuit between someone or something and mobil on that subject...

[NCHornet]

More Internet Myth!!! Please do a search for my reply on this same subject. If the bottle you have says anything about being dual rated Mercon/MerconV I wouldn't use it. Your manual specifically says not to use Mercon V, only Mercon/Dexron III is the only approved fluid. Then all of a sudden Ford comes out and says it's all of a sudden okay, some claim there was a reformulation, this is a lie!!! I did the research and no reformulation has ever been done. Again I really don't feel like going through all this again. If you can't find it, PM me.

If your trans has been rebuilt, the newer seals are compatible with the Mercon V , if not you should only use Mercon/Dexron III. This fluid was no longer manufactured after June of 2007, so I would stock up.

NCH