III or V; the Mercon debate

[Four0Sport]

I was looking into doing a pan drop and fliter change on my 97 5.0L but cant figure out what fluid came in my vehicle factory. Books at work say III, read some threads that said V, and the back of V bottles say it is a suitable replacement for III. Or is it?

Called a local ford garage and spoke to someone at the service desk who assured me that in 1997 my explorer came with Mercon III. He went on to say that they (Ford) do NOT reccommend mixing III and V and that when they service a vehicle with III they do a complete flush and refill of Mercon V bc Motorcraft Mercon III is no longer available to them? yeah, thats weird.

I have a small stockpile of Valvoline MaxLife Mercon III and hope I am doing the right thing by putting it in my truck. Questions, concerns, thoughts?

 

[aldive]

If it were me, I would go with a full synthetic ATF such as Amsoil.

Dead Link Removed

Good luck ....

 

[Turdle]

NOOOOOOOOOOOOOOOOOOOOOOOOOOO! Not the mercon III !!!!!!!!!!!!!!!!

Use the new mercon which is mercon 5 standard compliant-
I also recommend Amsoil-however any of the new mercon fluids will do-


The new standard means you cannot get the "lower" grade stuff anymore-(merc III for example).

 

[Four0Sport]

I understand Mercon V is a replacement for mercon III but i am only replacing maybe what.. 6 quarts when doing a pan drop? and ford does not recommend mixing fluid so what do i put in there?

 

[JDraper]

Yes, Mercon V or a synthetic would be better, but since you already have a stash of Mercon III, you can use that to do a change. However, when you run out of it, you will have to do a full swap to Mercon V or synthetic as has been stated.

The tranny was designed to use III, so it won't be a problem to continue to use it.

 

[aldive]

I understand Mercon V is a replacement for mercon III but i am only replacing maybe what.. 6 quarts when doing a pan drop? and ford does not recommend mixing fluid so what do i put in there?

After changing the filter via a pan drop, do a complete flush with the new ATF ( hopefully you will go full synthetic).

 

[Turdle]

Don't risk the entire transmission to save a few $$$

You have the advice-now it is your decision.

 

[BrooklynBay]

Only use Mercon III on your 93. Use Mercon V on your 97. Lubegard has a special additive to use when you have Mrecon III in a transmission which requires Mercon V. It provides the necessary friction modifiers which Mercon III lacks. This could cause slippage problems if it's not in there. Check this link for more information: http://www.explorerforum.com/forums/showthread.php?p=1348273

 

[MountaineerGreen]

With the 5.0, you can drain the torque converter as well, making it easy to do a complete drain. A pan drop may get 1/2 of your total fluid, a full drain is much better, IMO.

 

[CDW6212R]

Whew, lots of learning needed around the world.

There is no such thing as Mercon III. Again Mercon III is not a proper name for any ATF.

The bottles that you see with Mercon/Dexron III are meeting the specs of two fluids, Mercon, and Dexron III. That is Mercon (I) fluid, not Mercon III(no such thing).

Anyway, the Mercon is still available where the stores have not sold out of it. The difference in price is about a dollar, don't skimp on ATF, buy the best that you can afford.

You should be able to afford a few quarts of Mercon V, it is recommended for any electronic shifting Ford trans. It can be used in the old Explorers, the older transmissions are generally better off with the old pre Mercon V spec fluids.

I also agree that the top level synthetic ATF's are the best choice, they may save you a lot more in fuel mileage than the extra cost of the fluid($7 or so per qt.).

FYI, the new fluid past Dexron III is now Dexron VI, I would suggest not mixing that with the Mercon I, or V in our Fords. It may turn out to be compatible, but let's not jump to that conclusion yet. Good luck,

 

[GeorgeR]

Mercon V

OK, WTF, I put Castrol Mercon V in my '96 5.0.
Is my trans going to blow up or what? Does anyone really know what is up with this crap???

 

[GeorgeR]

Does anyone know what atf I should use?? The dipstick says Mercon?

 

[MountaineerGreen]

Mercon V replaces all other mercon products, it is advised to use it where possible. You did the right thing putting the mercon V in.

 

[reserved50]

V is just more slippy and lubes bearings better? You could put type F in and have lots of shudder and hard shifts and wear the internals out quicker, anything will work but the trans wont last.

 

[GeorgeR]

Great, I think I'm getting an occasional shudder when shifting into hi OD. Anyone want to venture an educated guess on what's up with that?? BTW I only changed what was in the pan. Haven't changed the tc yet.
Thanks

 

[CDW6212R]

A Valve Body kit would be wise for any transmission, especially when there are symptoms.

 

[GeorgeR]

OK, what's invoved in putting in a valve body kit? I've only done one slush box, a C6 about 20 years or so ago. I'm an old stick shift guy. (emphasis on old)

 

[CDW6212R]

They are easy for anyone who has done auto transmissions before. For others it's a matter of a lot of patience and watching details very carefully. The bolts need to be torqued to low #'s, like 90 inch pounds, or 110 in/lbs. depending on the trans. The holes drilled need to be correct and clean. Cleanliness is 90% of the job, trans fluid will get all over you. Use a very very large drain pan, and drip pan(2'x3'). The basic correction kits($35) don't take too long, the HD kits can be more involved, plus cost more($100). Check out a couple of threads here where others have done it. If the mileage is high, changing the electric solenoids is wise, as well as the servos/accumulators in the case, plus the Sonnax fix-it parts. The parts aren't very high for those items, and the possible gains in trans life is high.

 

[GeorgeR]

Thanks to BB I found some tech info on my 4R70W and thanks for your input. Can the kits be installed with the trans in the truck? Or does it have to come out. I have the nec torque wrenches and other tools or will buy what's necessary when the time comes. It's just now approaching 100k miles.

 

[BrooklynBay]

Only the valve body has to be removed for the shift kit.