Dexron VI is NOT fully backward compatible (Allison).

[ktlimq]

According to Allison, Dexron VI (six) is not fully backward compatible. Some seals compatible with Dexron III are not compatible with Dexron VI.
http://www.macktrucks.com/assets/mack/Service%20Bulletins/sb019006.pdf

What about Mercedes vehicles' transmissions designed for Dexron II or III? Are these seals compatible with Dexron VI?

Does MB USA have official position about Dexron VI?

Dextron is a licenced name. III is no longer going to be licenced so you pretty much only have 1 choice: VI.

[ktlimq]

Originally Posted by ForcedInduction

Dextron is a licenced name. III is no longer going to be licenced so you pretty much only have 1 choice: VI.

Major oil companies continue to make ATF for Dexron III, II applications. For example, Castrol USA sells Import Multi-Vehicle ATF and High Mileage ATF which are for Dexron II ~ III H applications and Mercedes Sheet 236.x.

Allison is updating seals and O-rings of some of their transmissions in order to make them compatible with Dexron VI, but we do not update seals and O-rings our MB transmissions manufactured in the 80's and 90's or earlier.

[rodnex]

any news or experiences?

[pawoSD]

I've been running Dexron VI in all of my MB's for years, all of them shift great.

Maybe Allison just uses junky seals.

IMHO they shift better on VI than on dino III

[Hey-Hof]

Good to know. I counldnt find any III and had to use the VI.

[cliffmac]

I disagree, Dexron is fully compatible with prior Dexron issues...no question...plus it's all bullcrap anyway.....believe me, this is mostly marketing.....

[cliffmac]

Do you even know how an automatic transmission even works?

[pawoSD]

Originally Posted by cliffmac

Do you even know how an automatic transmission even works?

Indeed I do.

I read/learn about how anything I come in contact with is made or works. From the coal mined to run the power plants to the socket in the wall, from the oil well to the engine.....from the field to the plate. And from toilet back to nature. I read WAY too much on those types of things.

[ktlimq]

I changed back to a Dex III equivalent from Dex VI (Pennzoil Dex VI). The tranny shifts better (including in New England winter).

Castrol USA, who sells Dex VI products in the US from which they can earn more money, recommended me their Castrol Domestic Multivehicle (a Dex III - H equivalent) for my vehicle: 1992 300D. I asked again whether Dex VI is better than Castrol Domestic Multivehicle saying that I am looking for the "best" for my car, but they recommended Castrol Domestic Multivehicle again.

I also changed from Mobil 1 75W-90 to Valvoline Durablend 80W-140 for my rear differential,
from Shell 5W-40 to Shell 15W-40 for my engine.

My car runs on original tranny, differential (very noisy), and engine. 316700 miles on it.


By the way, while I was looking for ATF for my car, I found an interesting fact. An MB dealer in Somerville, MA, uses Autozone brand Dex III equivalent for old MB's, which is even cheaper than the Dex III equivalent from Castrol, Pennzoil, Mobil, etc.

[pawoSD]

I cover 2,500 miles a month in my 300SD with Dexron VI in it....shifts perfectly every time. Shifting on the VI synthetic in the winter is MUCH better than on dexron III.

[hey_allen]

I'm all for using a better product when one exists for the application that needs it, but in this case, I still run Chevron DM3 (Dexron/Mercon 3 equivalent) year round, and buy it by the gallon at the local mcparts store whenever I need more.

The license for the Dexron name to be used on the Dexron3 product has expired, but the standard still exists, and the fluid is still made, it just can't be marked as Dexron any more.
Marketing, pure and through.

The Dexron6 stuff is a different base stock that it's made from, and while some transmissions are fine with it, I've heard that at least a few applications are specifically not accepting it, due to the different properties.
It's also supposed to be designed with different friction/lubricant behavior than the older DM3 ATF, but I don't know the specifics there.