Did Dexron and ATF+4 Kiss and Make Up?

[dan0928]

Everything I've heard on the Web and from mechanics I've talked to indicates that Dexron VI has no place in my Dodge Ram 3500 (545RFE) transmission and that, if mixed in with my ATF+4, it will lead to a premature failure. Chevron, however, is promoting Havoline Synthetic ATF Multi-Vehicle Dexron-VI, now called "Havoline Full Synthetic Multi-Vehicle ATF" to remove the term Dexron (per Chevron), as a "recommended" alternative to ATF+3 and ATF+4 in "late model" Chrysler transmissions. It is not an "approved" fluid, Chrysler has not approved its use. Chevron offers a VERY limited warranty on applications in Chrysler products where ATF+3 and ATF+4 are approved and by the time any damage is done, if you're even aware of the warranty, it will most likely have become void.

Have things changed? Is it now OK to use Dexron VI in my Dodge RAM 3500 trans?

My mechanic used it in a recent filter/fluid change and never informed me. I never would have approved the substitution. It seems that if my vehicle were still under warranty this would surely have voided it. Doesn't a mechanic have an obligation to get my approval before using an unapproved product in my vehicle?

 

[4WD]

Lots of internal R&D is done with a specific ATF - there are long powertrain warranties at stake.
I will not go there - and Dex VI is good stuff where it belongs ...

 

[901Memphis]

Some of the newer transmissions are more forgiving on not using ATF+4, especially the heavy duty units. If you use DexronVI in an older front wheel drive ATF+4 application, you would know you used the wrong fluid immediately because of how poorly it shifted.

 

[demarpaint]

I'd stick with the transmission fluid the vehicle calls for, stick with ATF+4. I'd have the mechanic change it to ATF+4 and do a line exchange to be sure he got all the fluid out and replaced with ATF+4. I wouldn't want to hear his story backing up his decision either.

 

[440Magnum]

From what I gather, Dex VI is a lot more similar to ATF+4 in friction modifier characteristics than previously. A friend tried it in a beater K-car with the much feared and fragile 41TE, and had no ill effects for a few years until a mechanical failure ended the transmission and the car (can't really call it fluid related when a mental part fractures). The viscosity isn't quite the same so I personally would be a little hesitant, but everything I gather says it's not the kiss of death that it once was.

 

[dan0928]

Originally Posted By: 901Memphis
Some of the newer transmissions are more forgiving on not using ATF+4, especially the heavy duty units. If you use DexronVI in an older front wheel drive ATF+4 application, you would know you used the wrong fluid immediately because of how poorly it shifted.


My 2005 would seem to be the "older front wheel drive ATF+4 application" but the only thing I've noticed so far is a bit of slipping while accelerating from a stop while towing my boat and some heavy metal klunking while going in and out of reverse to park or neutral. Would 6 quarts of Dexron VI in a 15 quart trans cause the shifting problems you're describing?

 

[Lyman]

My Jeep uses ATF+4 and I wouldn't think of trying anything else.

 

[RoadRaceJosh]

I wouldn't put a substantial amount of Dexron VI in place of ATF+4 even if the add pack was identical as the viscosity is decidedly not the same. And the VI of the ATF+4 is much better. This is the correct Havoline fluid: http://www.havoline.com/en-US/products/transmission-fluids/ATF.html https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=301779&docFormat=PDF

Compare to: https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=301779&docFormat=PDF

And this from Mobil...

Typical Properties

Mobil DEXRON-VI ATF
Viscosity
cSt @ 40ºC 29.5
cSt @ 100ºC 5.83
cP @ -40ºC 11,500
Viscosity Index 145
Flash Point, ºC (ºF) 220 (428)
Gravity, API 35.76
Color Red

Mobil ATF+4®
Viscosity
cSt @ 40ºC 34.4
cSt @ 100ºC 7.5
cP @ -40ºC 8,800
Viscosity Index 194
Flash Point, ºC (ºF) 200 ( 392)
Pour Point, ºC (ºF) -50 (-58)
Gravity, API 34.7
Color Red

 

[901Memphis]

It is the add pack that is the issue here not the viscosity. ATF+4 has a different coefficient of friction.

 

[Whitewolf]

I was just about to comment. ATF+4 is not as shear stable as DEXRON-VI nor is it as stable in oxidation or as durable in terms of friction. It's probably fine for what it was designed for but I wouldn't use it in a different application. However since it is the recommended fluid for the OP's transmission personally I would stick with that.

 

[dan0928]

Originally Posted By: Joshua_Skinner
I wouldn't put a substantial amount of Dexron VI in place of ATF+4 even if the add pack was identical as the viscosity is decidedly not the same. And the VI of the ATF+4 is much better.


Pardon my ignorance. Something new to me here. What is an "add pack"?

 

[4WD]

Cocktail of additives for many functions ...

 

[440Magnum]

Originally Posted By: Whitewolf
I was just about to comment. ATF+4 is not as shear stable as DEXRON-VI nor is it as stable in oxidation or as durable in terms of friction. It's probably fine for what it was designed for but I wouldn't use it in a different application. However since it is the recommended fluid for the OP's transmission personally I would stick with that.


All true, but then it IS an older spec. It's not like ATF 4 is an SG oil compared to Dex Vi being an SN. They're both excellent, stable, synthetic fluids. Dex, being newer, just tightens the requirements for shear stability snd low oxidation down a bit more.

The key point is that while more similar then ever, they do have different specified friction modifier characteristics that *might* lead to TC clutch shudder if Dex VI were used in some particularly sensitive Chrysler and Hyundai transmissions.

 

[demarpaint]

Originally Posted By: 440Magnum


The key point is that while more similar then ever, they do have different specified friction modifier characteristics that *might* lead to TC clutch shudder if Dex VI were used in some particularly sensitive Chrysler and Hyundai transmissions.


Which is why I suggested earlier that the OP return it to the guy that took the liberty of using the wrong fluid and have him redo the job, or better yet refund the money.

 

[dan0928]

Originally Posted By: dan0928
Originally Posted By: 901Memphis
Some of the newer transmissions are more forgiving on not using ATF+4, especially the heavy duty units. If you use DexronVI in an older front wheel drive ATF+4 application, you would know you used the wrong fluid immediately because of how poorly it shifted.


My 2005 would seem to be the "older front wheel drive ATF+4 application" but the only thing I've noticed so far is a bit of slipping while accelerating from a stop while towing my boat and some heavy metal klunking while going in and out of reverse to park or neutral. Would 6 quarts of Dexron VI in a 15 quart trans cause the shifting problems you're describing?


Think I needed a day or two off! Just noticed that you said "front wheel drive" and I even repeated it! Of course my truck isn't a "front wheel drive". Sometimes I amaze myself!

 

[DWC28]

Originally Posted By: Whitewolf
I was just about to comment. ATF+4 is not as shear stable as DEXRON-VI nor is it as stable in oxidation or as durable in terms of friction. It's probably fine for what it was designed for but I wouldn't use it in a different application. However since it is the recommended fluid for the OP's transmission personally I would stick with that.


Whitewolf: How important is shear stability, oxidation stability and friction stability if you change your transmission fluid every 30,000 miles? Do you think OEMs will ever standardize on a friction test and parameters so we can compare apples to apples?

 

[Hootbro]

Originally Posted By: dan0928
..........Doesn't a mechanic have an obligation to get my approval before using an unapproved product in my vehicle?



In a perfect world yes but the reality is especially if you took it into an independent shop/mechanic, the do not care and will use whatever "universal" fluid they can get their hands on cheapest and use that.

 

[RF Overlord]

Originally Posted By: dan0928
the only thing I've noticed so far is a bit of slipping while accelerating from a stop while towing my boat and some heavy metal klunking while going in and out of reverse to park or neutral.
Did it do these things before the fluid change? If not, I think you answered your own questions. Insist your alleged "mechanic" make it right.

 

[demarpaint]

Originally Posted By: RF Overlord
Originally Posted By: dan0928
the only thing I've noticed so far is a bit of slipping while accelerating from a stop while towing my boat and some heavy metal klunking while going in and out of reverse to park or neutral.
Did it do these things before the fluid change? If not, I think you answered your own questions. Insist your alleged "mechanic" make it right.


+1 I'd he's having problems, and they'll only get worse.

 

[Whitewolf]

Hello,

In answer to your question it can indeed be very important depending in the type of operation. For a start I don't know if you know that typically shear is not linear so most of the viscosity loss occurs within say 4 to 5 thousand miles. Oxidation depends upon the formulation, which in some 'recommended' fluids may or may not be to a standard that some of us expect.
As far as friction is concerned then one has to accept that OEMs use different designs, different materials and different control systems so the possibility of common tests and requirements is to say the least remote. That is why I, and several others, have spoken out in saying that so called 'universal' fluids are truly an impossibility if you compare their actual performance with many of the specification requirements relating to applications for which they are 'recommended'.
Does that help at all?