Transynd Fluid?

Don't know anything about the Dex III level H spec testing.

TES-295 was (likely still is) the gold standard for durability performance both in the lab and the our toughest "real world" applications. We had fleets where petroleum based Dex IIIs looked like shoe polish after 50,000 miles and Transynd was still going strong at 100,000 miles.
 
Tom Johnson is providing time and expertise on Dieselplace forum to answer questions about Allison transmissions and TES 295 fluid. This is his response to a question about TES 295 not meeting DEX IIIH spec by gmctodd. I don't know if it has ever been posted here or not. The questions and answers were easier to distinguish on the original post since TJ used red for his response.

I read on another forum that TranSynd could not meet the DexIII(h) requirement and lost liscensing when it went from (g) to (h).

1. Is this true? It is true. When GM wrote the DEXRON-IIIH spec they changed seal materials and test limits (I was part of that). We later found out that the GM factory fill fluid also could not always pass the seals tests because of (2) seal materials (namely N1, a nitrile rubber, and P3, a polyacrylate rubber). These two materials tended to experience slight shrinkage in many DEXRON-IIIH fluids including the GM factory fill fluid. TranSynd passed all the other DEXRON-IIIH tests with flying colors but it had problems with the (2) materials that showed shrinkage after the test. As you say, TranSynd did have a DEXRON-IIIG license number; but, in Allison's opinion, it was no longer necessary for TranSynd to carry a DEXRON-IIIH license since Allison customers were buying it for the TES-295 qualification and not for the DEXRON-IIIH certification anyway.
2. Does it matter? Meaning do the viscosity and oxidation benefits of TranSynd outweigh the differences between the DexIII (g) and (h) specs? No, in Allison's opinion, it didn't and doesn't matter. As I said, it's not like it failed oxidation, friction or viscosity; the failure had to do with slight shrinkage in (2) seal materials that many other DEXRON-IIIG formulations also had the same problem including the GM factory fill. The other performance parameters were much better than DEXRON-IIIH (viscosity stability and oxidation stability).
3. What are the differences between the (g) and (h) spec? Because for a fluid to meet TES 389, it must first meet DexIII(h) specs. (so they must be important). There were upgrades to friction and oxidation performance and GM also changed the seal tests and seal passing limits in DEXRON-IIIH vs the older DEXRON-IIIG spec. TES-389 is basically the same as DEXRON-IIIH except it includes an added test for Viton seal compatibility. We did this because some DEXRON-IIIH formulations tended to attack Viton seals just like DEXRON-VI did. We just wanted to sort out the bad ones so we let any DEXRON-IIH fluid test to see if they could pass the Viton seal test. It was easier than coming up with a whole new spec and new tests. I know that gets a little complicated.

Finally, If the DexIII spec is no longer validated how would somebody get a fluid TES 389 approved? Good question. Answer is they can't .... not yet anyway. Allison is currently in the process of rewriting the TES-389 specification to make it a "stand alone" specification. It will include all of the same type tests that were included with DEXRON-IIIH so oils that pass will be essentially the same quality as former DEXRON-IIIH fluids. This will allow oil companies to test their D3M products and get them qualified to an industry specification again. This is being done because GM will no longer review these older fluid formulations; they're only interested in approving DEXRON-VI fluids.

PS: I've seen some folks on these forums talk about DEXRON-IV (4). It never existed except in R&D. It never saw the light of day. So, GM went from DEXRON-III (3) to DEXRON-VI (6). They skipped DEXRON-V (5) because it sounded too much like Ford's MERCON-V (5) spec.

Here is a a Q&A related to the seal compatability issue that caused TES295 to fail DEX IIIH:

Quote:
Originally Posted by Kagolu
Was the slight seal compatibility/shrinkage issue resolved or corrected?
Kagolu,

It's been a long time since this all happened and I believe now that those (2) seal materials (N1, nitrile and P3, polyacrylate) have been removed from GM and Allison oil specifications. In the case of the N1 (nitrile) material, it really doesn't matter anymore because this material is not used as internal transmission seals; it's only used in o-rings where they are for External Use Only and contact with the fluid is not an issue. I'm really not sure about the polyacrylate and whether or not that matters anymore. Modern Allison specifications require testing on production seal materials that are used in such things as input and output seals and clutch piston seals.

Sorry but that's about all I know about those troublesome seal materials from about 10 years ago. In general, I do not think anyone should be concerned about this issue since the shrinkage was always very small (less than 1%). I do not believe that anyone would experience leaks or have seal issues because of this affect on these (2) materials.
 
what's the deal with Dexron-VI (6) with Allison 1000 transmissions in the light duty trucks, specifically the 6-speed in my 2006 Sierra ?

There seemed to be some people online who posted that dexron-vi did not meet TES-295/389 therefore it was not a good choice even though GM says it's backwards compatible with everything that ever called for dex-iii. I think I may have also read something about the transfer cases too, or maybe it was just about the transfer cases and not the allison (don't remember).
But I know in the owners manual for my 2006 sierra 2500hd, for the M74 allison transmission it says Dex-6 but for the transfer case it says Dex-3.
 
Allison and GM have parted ways and GM say DEX VI for Allison transmissions. Allison say to use TES 389 or preferably TES 295 fluids.

GM changed the fluid spec for transfer cases that formerly used DEX III. They printed in the manual to use DEX VI, then in a bulletin said to use GM Transfer case fluid, which I think is also for some manual transmissions. Many believe it to be similar to DEX III fluid.
 
Originally Posted By: Whitewolf
Originally Posted By: onion
Originally Posted By: Whitewolf
Yes I do happen to know.


Awesome. Now could you give us some detail as to what specific criteria Trasnynd failed to meet? And some data to go along with it?

Thanks.


I think that I have already done that and quoted SAE papers to support my opinion.


Whitewolf- Is the info in the SAE paper about Transynd failing to meet DEXIII H specs consistent with TJ stating it is due to causing shrinkage of a few nearly obsolete seal materials? Since Allison had to change some seal materials to allow DEX VI, it seems Transynd is friendlier to seals than DEX VI. As noted DEX VI doesn't meet DEX III H either, and if tested for that obsolete spec, it would likely fail for the same reason as Transynd.

It appears to me based on the info at hand, your contention that DEX VI is a superior fluid than Transynd, if based on Transynd's failure to meet DEX III H specs, is a faulty conclusion.

Allison went through an expensive process to develop Transynd and the result is a fluid that doubles the change interval in severe conditions such a garbage trucks that may endure 30 or more duty cycles/mile.

A chosen base oil isn't the last word of fluid performance, but when PAO is specified, it indicates a desire to formulate a durable and stable fluid that offers superior performance at both ends of its operating temperature range. DEX VI, at best a group III and possibly a blend, isn't likely to be as durable in extreme conditions as a PAO based fluid such as Transynd.
 
Originally Posted By: ledslinger
Originally Posted By: Whitewolf
Originally Posted By: onion
Originally Posted By: Whitewolf
Yes I do happen to know.


Awesome. Now could you give us some detail as to what specific criteria Trasnynd failed to meet? And some data to go along with it?

Thanks.


I think that I have already done that and quoted SAE papers to support my opinion.


Whitewolf- Is the info in the SAE paper about Transynd failing to meet DEXIII H specs consistent with TJ stating it is due to causing shrinkage of a few nearly obsolete seal materials? Since Allison had to change some seal materials to allow DEX VI, it seems Transynd is friendlier to seals than DEX VI. As noted DEX VI doesn't meet DEX III H either, and if tested for that obsolete spec, it would likely fail for the same reason as Transynd.

It appears to me based on the info at hand, your contention that DEX VI is a superior fluid than Transynd, if based on Transynd's failure to meet DEX III H specs, is a faulty conclusion.

Allison went through an expensive process to develop Transynd and the result is a fluid that doubles the change interval in severe conditions such a garbage trucks that may endure 30 or more duty cycles/mile.

A chosen base oil isn't the last word of fluid performance, but when PAO is specified, it indicates a desire to formulate a durable and stable fluid that offers superior performance at both ends of its operating temperature range. DEX VI, at best a group III and possibly a blend, isn't likely to be as durable in extreme conditions as a PAO based fluid such as Transynd.


There seem to be a lot of questions in there, I shall answer what I *think* you are asking.

Regarding the seals. TranSynd failed the seal testing, so the answer is "no" TranSynd is not more seal friendly than a DEXRON(R)-VI fluid.

Regarding TranSynd failing DEXRON(R)-IIIH testing. Yes, it failed on the seals, but also apparently exhibits undesirable friction characteristics over time. For clarification, please look at the end torque shown in the SAE Paper and you'll see what I'm talking about.

Your statement that current DEXRON(R)-VI fluids would NOT pass the now obsolete DEXRON(R)-IIIH testing is true. BUT not because as you state it would "fail the seal testing" but because the new specification has a completely different viscometric profile, meaning, the newer generation fluids wouldn't even get through the bench testing. So although you're correct in saying that DEXRON(R)-VI fluids wouldn't pass the obsolete spec, unfortunately NOT for the reasons you are stating.

Let me give you an example : the old DEXRON(R)-IIIH fluids would start off typically at a KV/100'C of about 7.5-7.8 cSt. By 80,000 miles, they would typically have dropped to about 4.1 or 4.2 cSt. If you take a look at the published data, you'll observe that although a typical DEXRON(R)-VI fluid starts off at only about 6 cSt, after 200,000 miles they are typically still above 5 cSt.

That kind of data just proves, yet again, what I have been stating, that DEXRON(R)-VI fluids exhibit far superior performace than the older, DEXRON(R)-IIIH type fluids, which are of course no longer 'truly' available. Any company can put a DEXRON(R)-IIIH claim on a lable using suitable 'weasel-wording' but without GM policing those obsolete specs, you could be purchasing any old rubbish.

And finally, and you're probably bored by now ... but to answer your question about PAO type fluids being more durable, you have to realise that the use of PAO came into its popularity at a time when most oils were formulated with Group I base stocks. So, yes, at THAT time, it was a massive improvement in durability in terms of oxidative stability primarily.

However, that's around a 20-yr old "concept" and these days, you'll find that similar performance can be achieved by the use of Group III, Group III plus and/or combinations of those base stocks WITH PAO.

I hope that my comments have helped to show you that this really isn't an easy "it passes/it doesn't pass" question, but a far more complicated and far reaching industry objective to achieve continuous improvement which is obvious from published information and data from multiple OEMs.

At the end of the day, if you want to buy TranSynd and use TranSynd then nobody will try to stop you. It's a perfectly decent fluid for its intended application. I just want to make sure people are aware that the latest DEXRON(R)-VI fluids are far, far superior in durability and performance so they can make an informed decision on what to purchase.

Hope that has helped.
 
Originally Posted By: Whitewolf
That kind of data just proves, yet again, what I have been stating, that DEXRON(R)-VI fluids exhibit far superior performace than the older, DEXRON(R)-IIIH type fluids, which are of course no longer 'truly' available. Any company can put a DEXRON(R)-IIIH claim on a lable using suitable 'weasel-wording' but without GM policing those obsolete specs, you could be purchasing any old rubbish.

Doesn't TES-389 replace the DEXRON(R)-IIIH specification for transmissions that require Dex 3?

Very thorough explanation, thanks.
 
Originally Posted By: Towncivilian
Originally Posted By: Whitewolf
That kind of data just proves, yet again, what I have been stating, that DEXRON(R)-VI fluids exhibit far superior performace than the older, DEXRON(R)-IIIH type fluids, which are of course no longer 'truly' available. Any company can put a DEXRON(R)-IIIH claim on a lable using suitable 'weasel-wording' but without GM policing those obsolete specs, you could be purchasing any old rubbish.

Doesn't TES-389 replace the DEXRON(R)-IIIH specification for transmissions that require Dex 3?

Very thorough explanation, thanks.


Not unless Allison put into place a test programme and approval & licensing process that matches the requirement of DEXRON(R)-IIIH as it stood before it was obsoleted.
 
Whitewolf- I am more difficult to bore than this. If Allison had to provide a serial number cutoff and upgrade seal materials for DEX VI, and all transmissions can use Transynd, then Transynd might be easier on seals.

Good point about the dramatic improvement of PAO vs group I, and the less impressive difference with group III.

Glad I have your blessings to use Transynd-I have a bunch of it!

"I just want to make sure people are aware that the latest DEXRON(R)-VI fluids are far, far superior in durability and performance so they can make an informed decision on what to purchase."

Do you base the above statement on: "apparently exhibits undesirable friction characteristics over time" or something else?
 
Originally Posted By: ledslinger
Whitewolf- I am more difficult to bore than this. If Allison had to provide a serial number cutoff and upgrade seal materials for DEX VI, and all transmissions can use Transynd, then Transynd might be easier on seals.

Good point about the dramatic improvement of PAO vs group I, and the less impressive difference with group III.

Glad I have your blessings to use Transynd-I have a bunch of it!

"I just want to make sure people are aware that the latest DEXRON(R)-VI fluids are far, far superior in durability and performance so they can make an informed decision on what to purchase."

Do you base the above statement on: "apparently exhibits undesirable friction characteristics over time" or something else?


TranSynd isn't easier on seals.
DEXRON(R)-VI is superior in all areas of performance, most specifically on friction characteristics and friction durability. Hence, the need to lengthen the duration of the friction tests in order to even see a deterioration in the newest fluids. Even then it's negligible.
 
Originally Posted By: Whitewolf


Regarding the seals. TranSynd failed the seal testing, so the answer is "no" TranSynd is not more seal friendly than a DEXRON(R)-VI fluid.

1.It appears GM's own fluid failed also. A quote from Tom Johnson to this question:" When GM wrote the DEXRON-IIIH spec they changed seal materials and test limits (I was part of that). We later found out that the GM factory fill fluid also could not always pass the seals tests because of (2) seal materials (namely N1, a nitrile rubber, and P3, a polyacrylate rubber). These two materials tended to experience slight shrinkage in many DEXRON-IIIH fluids including the GM factory fill fluid. "
2.Also, Dex VI failed the test for the viton seals in the early 06 Allison's.
Originally Posted By: Whitewolf
At the end of the day, if you want to buy TranSynd and use TranSynd then nobody will try to stop you. It's a perfectly decent fluid for its intended application. I just want to make sure people are aware that the latest DEXRON(R)-VI fluids are far, far superior in durability and performance so they can make an informed decision on what to purchase.

If Dex VI is far, far superior why does GM require a 50,000 mile service interval in the Allison. And Allison says Transynd can be used to 150,000 miles
 
Originally Posted By: Whitewolf


Regarding the seals. TranSynd failed the seal testing, so the answer is "no" TranSynd is not more seal friendly than a DEXRON(R)-VI fluid.

1.It appears GM's own fluid failed also. A quote from Tom Johnson to this question:" When GM wrote the DEXRON-IIIH spec they changed seal materials and test limits (I was part of that). We later found out that the GM factory fill fluid also could not always pass the seals tests because of (2) seal materials (namely N1, a nitrile rubber, and P3, a polyacrylate rubber). These two materials tended to experience slight shrinkage in many DEXRON-IIIH fluids including the GM factory fill fluid. "
2.Also, Dex VI failed the test for the viton seals in the early 06 Allison's.
Originally Posted By: Whitewolf
At the end of the day, if you want to buy TranSynd and use TranSynd then nobody will try to stop you. It's a perfectly decent fluid for its intended application. I just want to make sure people are aware that the latest DEXRON(R)-VI fluids are far, far superior in durability and performance so they can make an informed decision on what to purchase.

If Dex VI is far, far superior why does GM require a 50,000 mile service interval in the Allison. And Allison says Transynd can be used to 150,000 miles
GM & Allison parted ways. Why would Allison recommend using a GM fluid product at all?
 
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