Transmission fluid

[onebad8.1]

Hey guys ,well I just did a transmission drain and put a mag hy-tech pan on it,its a 2003 gmc 2500hd with the 8.1 and allison transmission. I filled it with valvoline max life full synthetic fluid it says it's recommended in gm dexron 2 3 6 and allison c-4,tes389 is this ok to run in my allison 5 speed transmission?

[DaveH71]

Yup, actually heard really good things about max life ATF. Their max life engine oil is good stuff as well.

[newdude]

TES-389 is the heavy duty truck spec. TES-295 is the fluid spec for the 1000. From the diesel forums and a couple of engineers, anything Dexron 3 or Allison Transynd is recommended in the 1000 unless per GM, is is a Dexron 6 factory filled transmission. Dex 6 can possibly harm the seals in older versions. Not sure how a one size fits all fluid will do in there.

[onebad8.1]

Thanks for the reply guys I'm goin to look in to getting some transynd

[Cowpie]

Actually TES 295 is the preferred spec across the entire Allison transmission game from the 1000 on up to the TC-10 TS in commercial semi trucks. TES 389 is allowed but has a shorter change interval recommendation that TES 295. All of this has nothing to do with whether it is an Allison in a pickup or an Allison in a heavy haul truck grossing 800,000 lb crawling hills in the Arizona heat.

 

 

http://www.allisontransmission.com/parts-service/approved-fluids/on-highway-fluids

[onebad8.1]

How many miles do you think, cowpie , could I go on the fluid I have in there now?and thank you for your input it is much appreciated.

[Cowpie]

That I really can't say. Depends on how much work you put on the Trans I would guess. I am only going by what I read at the Allison site on the different approved fluids. I didn't even know TES 389 existed till recently. I always thought TES 295 was the only approved fluid.

[vucelick]

Skip the transynd. I swaped to it a couple years ago after reading about it. After a while the trans started "flaring" the shift into 5th under light throttle. I talked to some fleet tranny guys and they suggested i change back. I did, end of problem. I have the 8.1/allison combo you have. I had never heard anything bad about transynd and with all theother good fluids out there that are less expensive i say run one of them instead. Just my experience.

[Black02Silverado]

You will be fine running that fluid. It calls for a dexron VI fluid per a GM TSB. From AMSOIL's look-up guide.

 

[3] This specification has been updated from Dexron II or III to
Dexron VI per a Technical Service Bulletin from the
manufacturer

 

As for how long to run it. Unless you tow or haul often, I would change out the filter and fluid every 50k miles, 30k if you work it hard.

[onebad8.1]

Thank you all for the information very much appreciate it, I'm just glad that I didn't put the wrong fluid in cus i love this truck and the 8.1 allion combo

Allison

[elcamino]

Fyi - Allison Transynd is a 100% PAO synthetic Dexron III ATF. Dexron VI is a semi-synthetic at best, its a mixture of Gr. II and Gr. III base oils.

[Cowpie]

I would suggest the reverse is true. Dex III is a semi synthetic and the Dex VI is full synthetic . After all, Dex VI is a lower viscosity requirement and better at oxidation control. VI supersedes III for this very reason. Dug this up for your perusal. You can see, Dex VI requires full synthetic because it has to have a lower viscosity than Dex III and also be substantially more shear stable than Dex III. This demands full synthetic. Dex III is the blend, Dex VI is the full synthetic. And Allison TES 295 is neither.

 

 

Dexron-VI

 

The fluid specification for Dexron-VI was introduced in 2005, and was first used as the GM factory-fill automatic transmission fluid for model year 2006. All Dexron-III licenses expired permanently at the end of 2006, and GM now supports only Dexron-VI fluids for use in their automatic transmissions, although fluids asserted by their manufacturers to meet Dexron-III standards continue to be sold under names such as Dex/Merc. These fluids are not regulated or endorsed by GM.

 

 

Dexron VI is of a slightly lower viscosity when new compared to the prior Dexron fluids (a maximum of 6.4 cSt at 100°C for Dexron VI and 7.5 cSt for Dexron III), but the allowed viscosity loss from shearing of the ATF during use is lower for Dexron VI, resulting in the same lowest allowed final viscosity for both Dexron III and VI (5.5 cSt). The lower viscosity is intended to gain improvements in fuel economy by lessening parasitic drag in the transmission. Since Dexron VI is not allowed to thin out (lower its viscosity) as much as Dexron III during use, it requires the use of higher-quality, more shear-stable (less prone to thinning while in use) base oils. The current GM specification that defines the fluid is GMW16444, which superseded the original specification, GMN10060.

[onebad8.1]

So the valvoline max life full synthetic is OK to run in the allison transmission,it says it's tes389 for allison

[elcamino]

I would suggest the reverse is true. Dex III is a semi synthetic and the Dex VI is full synthetic.

 

 

NO. GM Dexron VI is not a full synthetic, its a mixture of Gr. II and Gr. III base oils + additives.

Dexron III is 100% mineral oil, no synthetic in it.

 

NOTE - Speaking ONLY of GM Branded Dexron. There is nothing prohibiting manufactures from making a Dexron III and Dexron VI fluids that meet the requirements of both.

 

Here's the deal on the word "synthetic". A few years (1999) ago a big oil company had a Group III product that they called synthetic. Prior to that, only Group IV was called synthetic. The oil company won the BBB arbitration and after that the word synthetic has been "bastardized". It's come to mean lots of different things. So, it's "buyer beware" when it comes to synthetics. Unfortunate for everyone.

[Cowpie]

Ah. Got it. Thanks for the history lesson from 1999. Now let's use some logic.

 

First, Dexron VI replaced Dexron III in 2006 as the factory fill for GM. It is backward compatible with Dexron III applications, but Dexron III is not forward compatible with applications that require Dexron VI. Therefore, by implication, Dexron VI is a higher quality product with a better base and more robust additive package than Dexron III.

 

Second, No one really cares if it is called a synthetic, a group IV PAO, a group III, or just plain glop, as long as it does what is intended.

 

Thirdly, while 1999 is one thing, we are now in the second decade of the next century. Details surrounding oil and lube production has changed and improved exponentially since 1999. For your enjoyment, here is a link to an article in Machinery Lubrication that dispels the myths surrounding group III "faux synthetic" and group IV "true synthetic" Except in a laboratory setting, no one out here in the real world is going to be able to tell the difference, including the equipment that it is being put in. And one aspect that many just plain seem to miss.... a big part of what is in that bottle of ATF, motor oil, gear lube, etc is additive package. You can have the best Group IV PAO, but if it has a lousy add pack, it is less than worthless compared to a Group III with a great add pack.

 

http://machinerylubrication.com/Read/533/base-oil-trends

 

And one thing that escapes the Group IV PAO "purists" is that it is made from natural gas. Yep, that's right. PAO is made primarily from ethylene gas that is primarily sourced from good 'ol natural gas pumped from the ground just like oil. Many times, right out of the same well! PAO is just another carbon chain like any other oil. Slightly different structure, but a carbon chain molecule nonetheless. And the truth be told, the lubes made from whale oil back in the early 1800's, technically, are still classed as "true" synthetics. But I am quite sure I have no desire to run whale oil in my motor any time soon.

 

The buyer does not have to beware of anything except the classification of the product they are using for what purpose. i.e. that they are using a Dexron VI in a transmission or transfer case that calls for a Dexron VI. Or that they are using a 5w30 with the proper dexos1 or ILSAC GF-5 rating as per GM. Or that the 5w40 meets the dexos2 or CJ-4 classification. They do not have to give a rip if it is Group III or Group IV. If it meets the spec, then it is adequate. And for our purposes of this thread, that a proper TES 295 or TES 389 transmission fluid be used in an Allison.

 

No... Dexron VI is not a mixture of group II and group III. Else it could not meet the tight tolerances of the Dexron VI classification. It might be all group III or all group IV or a combination of the two, but there is NO group II in Dexron VI. The NOACK tolerance of Dexron VI could not be achieved using a group II, nor could the lower initial viscosity of 6.4 cSt at 100C compared to Dexron III 7.5 cSt at 100C be achieved with a group II. And the viscosity loss tolerance to a level of only 5.5 cSt at 100C is too tight for a group II to achieve also. Group III and Group IV synthetics are able to meet the criteria of Dexron VI. A group II and Group III could meet the broader tolerances of Dexron III. But then, it is an inferior product to Dexron VI. Thus, Dexron VI is a full synthetic by definition. You can quibble over whether a Group III is a synthetic or not, but that is a long dead argument according to the Society of Automotive Engineers, the American Petroleum Institute, and the Petroleum Quality Institute of America for starters. Who really cares what the BBB has to say on the issue anyway?