My truck is a 2005 4.6L. I had my transmission flushed today for the first time at 50,000 miles. I noticed on the invoice that he used dexron III even though on the dipstick it clearly says to use Mercon V. I called him about this, and he said its fine because now-a-days they're interchangeable.

Is he trying to break my transmission so that I'll have to go to him to repair it? This guy's had his transmission shop for 30 years, and my dad's done a lot of business with him so I hate to think he's being shady. This rough economy must be getting to some people...

 

i have NO clue but...
id say no matter what make him put mercon V in the truck. im sure hes not trying to screw you to the wall cuz thats a FAST way to hurt business with you telling everybody what hes doing. putting mercon V in it is for your peace of mind. so if it does go ::knock on wood:: for any reason you know its not the fluid. im sure he wont be happy but the stuffs cheap and he should do it.

 

They are interchangeable, it will be fine.

 

I have to disagree with the above poster dexIII is interchangable with regular mercon not merconV the difference is in the friction modifiers. I would deffantly recommend switching back to the merconV before you cause damage the torque converter is what usually goes first. Just my opinion but your old fluid was better than this out dated stuff

 

Get the Dexron out of there. Make him put Mercon V in.

 

Talked to the guy again and he swears that the dexron works...he doesn't even carry mercon v.

Isn't there an additive that I can put in to bring the dexron 3 up to mercon v spec? What's the stuff called and whats a good brand?

Thanks

 

Make him go buy the Mercon and replace the fluid. Just because he says it interchangable does not mean it is! Ford specs certain fluids for a reason. Use what they spec or something that meets or exceeds the spec.

Or better still, go to a shop that knows something about modern transmissions.

If it was me, I would have never left the shop until he either replaced the fluid or gave me a lifetime transmission warranty in writing.

 

The guy probably gets 55 gal drums of Dexron really cheap. You need to have your entire transmission flushed and all the fluid in it needs to be Mercon V. That is Ford's requirement, period. There is nothing to discuss and nothing more to say.

This guy should not be in business.

George

 

Since he does not carry the Mercon V, I'd suggest going back to the dealer (should have done in the first place), have them properly flush it and make the other fellow reimburse you.

I believe Mercon V is a full synthetic or a semi syn fluid.

Tim

 

Go to: www.imperialoil.com/Canada-English/Files/Products_Lubes/IOCAENPVLESATF_Mer_V_Dex_III.pdf

I copied the following from their spec sheet:

It appears to me that they are totally compatible.

 

They are...

 

This is NOT universally true. It may be true if the OP is living in Canada and got this specific ESSO transmission fluid in his transmission, but that is SOLD as Mercon V/Dexron III, not just Dexron III.

Ford has recently made its Mercon V backwards compatible with the old Mercon (because the stopped selling the old Mercon), but that does NOT mean that Dexron III's are compatible with the Mercon V spec UNLESS they have been tested and licensed as Mercon V.

OP: If you want to do further research, ask the trans guy who put in the Dexron III exactly what brand he put in, or better yet, take a look at the labeling on his bulk container. If it does not SPECIFICALLY state that the fluid meets Mercon V licensing requirements, it is still the wrong fluid. For instance, here is the US Valvoline trans fluid page....note that there is one fluid that is Mercon/Dexron III compatible (but not Mercon V) and a separate Mercon V:

http://www.valvoline.com/products/co...mission-fluid/

George

 

Goarge,

That was a great catch but if you click on the link under the DEX/MERC bottle, it states that this fluid is compatable in Ford vehicles 2005 and older. The OP has a 2005 F-150.

The Mercon V is Ford's exclusive fluid and must be used in '05/'06 and newer vehicles.

I can easily see where the confusion would come into play as my '99 Taurus calls for Mercon V as well as my '04 Expy.

I would still recommend a trip to the dealer and ask the question of compatability. The Dexron III may only be good to a certain point in 2005 and the OP's truck may not fall in that category.

Again George, great find. If I've mis-interpreted anything, please let me know. The last thing I would want is for someone to ruin their equipment due to a misinformed post.

Tim

 

Hey Tim...

Ford did not change from Mercon to Mercon V in one fell swoop, but rather did it transmission by transmission. Our old '98 Sable used Mercon V, whereas the Ford Escape used regular Mercon through 2007.

The 4R70W in my 2002 E150 is a Mercon V box, and I'm assuming that the OP's trans is a 4R70W or 4R75W. He even said that it says Mercon V on the dipstick.

The "2005 and older" on the Valvoline site is an oversimplification. It's similar to Ford changing over engines to 5W20 oil in 2002 (and back-speccing some older engines for 5W20), but still requiring 5W30 in the Explorer 4.0 through 2010. Note that GM has gone from Dexron III to Dexron VI, and the 2005 might allude to the change in GM spec. The Valvoline Dex/Merc description specifically says "Approved for all GM and Ford vehicles except where a Ford MERCON® V or Type F fluid is recommended." That is very clear.

I will note that the Dexron VI description allows it to be used in place of Dexron III and even Dexron II--just as Motorcraft Mercon V is now allowed as a substitute for the older Mercon. BUT this does not mean that Dexron III can be used in place of Dexron VI nor does it mean that Mercon can be used in place of Mercon V.

There is also a Mercon SP for some of the heavy truck trans applications, which is yet a different standard. And Mercon LV, which is different yet... It is getting really hard to tell the players apart without a program

Hope this helps,
George