Three ATF's Analyzed

[MolaKule]

Originally Posted by bulwnkl
Originally Posted by MolaKule

It is unfortunate they didn't address the zinc-to-phosphorus ratio differences and how that affects Anti-Wear performance.


Indeed, that would have been interesting reading.


It males me wonder if Idemitsu even knows this is a dual-shaft automated manual transmission. The same with Valvoline and any other company who claims coverage or equivalency for DW-1.

 

[bulwnkl]

Perhaps I was just hoping for more from Idemitsu than what I read as the equivalent of:
"Don't worry, it's fine. Look, the kinematic viscosity is pretty much the same, so it's totally suitable! We acknowledge that it's very different from Honda's own fluid, but it's really good."

That's a response I would expect if they're aiming their comment at a user they think knows little about ATFs and will not understand whatever they say anyway. I just think it would have been much more illuminating and helpful to address the trade-off(s) of the very different formulating strategies employed between them and Honda. The completely different clutch materials would be an interesting thing to touch on, for example.

 

[MolaKule]

I'll cross post this info here because I think it is relevant:

The totality of the Friction Modifier "group" in Step-Shift ATF's consist of the mixture of Calcium, Magnesium, the dispersant, and the organic friction modifiers.

The Anti-Wear group consists mostly of the phosphorus-boron chemistry with some minor sulfur chemistry.

In DW-1 the Calcium level is 1.5 X the nominal levels seen in Step-Shift fluids,

In DW-1 the Magnesium level is 68 X the nominal levels seen in Step-Shift fluids,

In DW-1 the Phosphorus level is 0.0035 X the nominal levels seen in Step-Shift fluids,

In DW-1 the Calcium level is 1.5 X the nominal levels seen in Step-Shift fluids,

In DW-1 the Zinc level is 100 X the nominal levels seen in Step-Shift fluids.

Which is why I stated in the Analysis above,

"...Owners' of Step-Shift automatic transmissions should avoid using this product in any Step-Shift automatic transmission...."

 

[Hall]

To them, if the viscosity (at varying temperatures) is the same, that's all that matters.

 

[JHZR2]

Originally Posted by MolaKule
Originally Posted by ctechbob
So, with all the discussion about H+ and DW1, I decided just for giggles to send off an email to Idemitsu. It took them about 2 weeks to get back with me, thought they never would, but here is a C&P of the response.

Hello, Shawn

Thank you for reaching out to Idemitsu Lubricants America Corporation.

Your concern is important for us, so we requested our technical department to provide additional information.

The DW-1 fluid requires specific properties (for example, viscosity, viscosity retention, low-temperature viscosity, etc.) and dynamic and static friction beside standard transmission oil properties...



I see they totally ignored (never made mention of) the huge disparity between the two additive chemistry's.


Well, can we get to the bottom of if there are, or are not more than one way to skin a cat?

From looking at so many oil industry Q&As, spec sheets, etc., unless there is a spec or standard for the additization, (a) there may be more than one approach to achieving a key measurable characteristic, and (b)the manufacturers likely will claim it as proprietary and not care to discuss.

Unfortunately totally normal.

They did hit on similar friction characteristics. I wouldn't expect them to touch on how x ppm of this equates to y ppm of that.

For me, I just but OE DW-1.

 

[MolaKule]

Originally Posted by JHZR2
Originally Posted by MolaKule
Originally Posted by ctechbob
So, with all the discussion about H+ and DW1, I decided just for giggles to send off an email to Idemitsu. It took them about 2 weeks to get back with me, thought they never would, but here is a C&P of the response.

Hello, Shawn

Thank you for reaching out to Idemitsu Lubricants America Corporation.

Your concern is important for us, so we requested our technical department to provide additional information.

The DW-1 fluid requires specific properties (for example, viscosity, viscosity retention, low-temperature viscosity, etc.) and dynamic and static friction beside standard transmission oil properties...



I see they totally ignored (never made mention of) the huge disparity between the two additive chemistry's.


Well, can we get to the bottom of if there are, or are not more than one way to skin a cat?

From looking at so many oil industry Q&As, spec sheets, etc., unless there is a spec or standard for the additization, (a) there may be more than one approach to achieving a key measurable characteristic, and (b)the manufacturers likely will claim it as proprietary and not care to discuss.

Unfortunately totally normal.

They did hit on similar friction characteristics. I wouldn't expect them to touch on how x ppm of this equates to y ppm of that.

For me, I just but OE DW-1.


The problem is not a matter of friction characteristics but the fact they did not address the huge disparity between their (Idemitsu or Valvoline) chemical signature and the original DW-1 chemical signature.

The amount of zinc ester in DW-1 is there for a specific reason.

 

[JHZR2]

Originally Posted by MolaKule
Originally Posted by JHZR2
Originally Posted by MolaKule


I see they totally ignored (never made mention of) the huge disparity between the two additive chemistry's.


Well, can we get to the bottom of if there are, or are not more than one way to skin a cat?

From looking at so many oil industry Q&As, spec sheets, etc., unless there is a spec or standard for the additization, (a) there may be more than one approach to achieving a key measurable characteristic, and (b)the manufacturers likely will claim it as proprietary and not care to discuss.

Unfortunately totally normal.

They did hit on similar friction characteristics. I wouldn't expect them to touch on how x ppm of this equates to y ppm of that.

For me, I just but OE DW-1.


The problem is not a matter of friction characteristics but the fact they did not address the huge disparity between their (Idemitsu or Valvoline) chemical signature and the original DW-1 chemical signature.

The amount of zinc ester in DW-1 is there for a specific reason.


I thought that Zinc Esters (or is it only ZDDP?) were generally omitted from ATF because they turned red fluids brown?

If that was the case, I'd think it means that the Zinc antiwear function can be accomplished by something else?

Even if not, if reduction of zinc in motor oils still yields an acceptable, if not a superior result, couldn't the same be achieved here?

Is there something that the zinc we see there is doing, that absolutely nothing else can?

I've not seen the actual standard written by Honda for DW-1. If it doesn't prescribe a specific zinc content, I don't think it is necessary to be there. Other performance attributes are the parameters of interest.

If zinc is not specified in the standard, then the presence or lack thereof of zinc seems to me to be an academic curiosity. And not the first time an oil supplier wouldn't comment on their additives.

So what am I missing?

 

[Hall]

Originally Posted by JHZR2
I've not seen the actual standard written by Honda for DW-1.

So what am I missing?

There's no publicly available standard because it's proprietary (well, I presume this is the case). No one outside of Honda or their ATF blender can say definitively why they use "x" amount of zinc, for example. A chemist or mechanical engineer can speculate all day long without knowing for certain.

 

[JHZR2]

Originally Posted by hallstevenson
Originally Posted by JHZR2
I've not seen the actual standard written by Honda for DW-1.

So what am I missing?

There's no publicly available standard because it's proprietary (well, I presume this is the case). No one outside of Honda or their ATF blender can say definitively why they use "x" amount of zinc, for example. A chemist or mechanical engineer can speculate all day long without knowing for certain.


That's kind of my concern - how much is speculative versus functionality of a specific add that cannot be replaced in an ATF formulation.

I would think that if the ATF is considered "lifetime", through the warranty period, there's no need for Honda to provide a proprietary fluid free of charge.

So lack of spec then leaves further speculation of if either (a) there is a necessary Zinc additive that is not replaceable by any other additive in the mixture; or, (b) the adds are interchangeable, and friction and protection can be appropriately achieved with multiple formulations. Perhaps not 110% ideally, but good enough for analytical work.

 

[ctechbob]

FWIW, I have emailed Thomas back with some specific questions and a link to this thread. Don't know how detailed the response will be.

On another note, if a moderator wants to contact him and invite him to the site, for something akin to an AMA, I can send you the email address. As just a 'joe schmoe' here I think that is better handled by someone up the chain.

 

[bulwnkl]

Thanks for doing that, ctechbob.

 

[MolaKule]

Originally Posted by JHZR2

I thought that Zinc Esters (or is it only ZDDP?) were generally omitted from ATF because they turned red fluids brown?



Zinc compounds are still used in step-shift ATF DI packages as secondary anti-oxidants and metal deactivators, but in concentrations of < 5 ppm on the average.

Originally Posted by JHZR2
If that was the case, I'd think it means that the Zinc antiwear function can be accomplished by something else?


I had my colleague re-run another analysis (which I have been waiting for before responding further) and upon further inspection it appears the zinc component is a zinc dialkyldithiocarbamate which is a multi-functional additive that acts as an Antioxidant, Antiwear/Antiscuff, Corrosion Inhibitor, and Metal Deactivator, hence, a Multi-Functional chemistry.

Could an alternative set of chemistry be formulated to replace the Zinc DTC. Quite possibly, but what would it be?

Originally Posted by JHZR2
Even if not, if reduction of zinc in motor oils still yields an acceptable, if not a superior result, couldn't the same be achieved here?


Zinc reduction in motors oils, and specifically ZDDP compounds, are reduced to prevent metallic loading of catalytic converters, due to the possibility of metallic ash being carried into the exhaust stream and into the CAT. Transmission fluids of course never see combustion gases. I don't see a 1-1 comparison here.

Originally Posted by JHZR2
Is there something that the zinc we see there is doing, that absolutely nothing else can?


Quite possibly, but what would it be?

Originally Posted by JHZR2
I've not seen the actual standard written by Honda for DW-1. If it doesn't prescribe a specific zinc content, I don't think it is necessary to be there. Other performance attributes are the parameters of interest.

If zinc is not specified in the standard, then the presence or lack thereof of zinc seems to me to be an academic curiosity. And not the first time an oil supplier wouldn't comment on their additives...


As others have mentioned, if Honda has a standard, it has not been published and the original DW-1 is most likely a closely held internal formulation spec.

Reason for Analysis:

The analysis was conducted because of the many past discussions and questions here on BITOG surrounding comparisons of third party MV ATF's with respect to the Honda DW-1, Z-1, and the Idemitsu H.

In my Commentary and Opinion I stated this:
Quote
Commentary and Opinion: The chemical signature for this ATF is essentially the same as Honda's Z-1 fluid and is indicative of fluids used in Automated Manual transmissions. To the author's knowledge, no Step-Shift ATF chemical signature compares. Notable is the level of the Zinc compounds needed for the internals of Automated Manual transmissions.

Owners' of Step-Shift automatic transmissions should avoid using this product in any Step-Shift automatic transmission.


I continue to stand by that warning.

And here is the reason for the implied warning: In the beginning of Step-Shift AT fluid formulations ZDDP and other zinc compounds were used as the primary AW and AO agent. Later, it was found that metallic zinc, at the concentration levels being used, was infiltrating the pores of the cellulose-based wet-clutch materials.

Wet clutch's of the cellulose-composite types need a certain amount of porosity in order to soak up (disengaged condition) and expel fluid (engaged condition) in order provide the necessary dynamic FM required during shift transitions, and to also provide cooling of the clutch pack surfaces.

For a more thorough discussion of the "temperatures " encountered in AT operation, see:

https://www.bobistheoilguy.com/automatic-transmissions-study/

A Study of Internal Heat Generation and Its Effects on ATF

Zinc infiltration of the pores not only modified the fluid exchange process and modified the dynamic FM, but also accelerated glazing of the clutch pack surfaces.

Now, knowing the disparate ratios of zinc-to-phosphorus in DW-1 (or Z-1) to the signatures of currently marketed fluids for Step-Shift AT's, I think the warning still applies.


Quote
Conclusion: While this article may not settle all debates, one should closely examine these analyses and educate themselves on the various offerings and claims in order to determine "suitability" for their vehicles' transmission.

 

[ctechbob]

So here's my question then. Honda still uses multi-disk clutches in their transmissions, no different from a 'step shift'. From what I've seen, those clutch plates are made of the same materials as every other AT clutch plate out there, so how can the Zinc not hurt those, but would hurt a non-Honda trans?

 

[MolaKule]

Originally Posted by ctechbob
So here's my question then. Honda still uses multi-disk clutches in their transmissions, no different from a 'step shift'. From what I've seen, those clutch plates are made of the same materials as every other AT clutch plate out there, so how can the Zinc not hurt those, but would hurt a non-Honda trans?


Yes good question.

From this, https://www.liveabout.com/dual-clutch-direct-shift-transmission-533860

they do have similar clutch construction, but it has not been determined that the specific clutch material is the same type of material that is used in say GM or Ford or Nissan Step-Shift transmissions that use the porous cellulose-composite clutch face materials. My suspicion is (yet unfounded) is it is either of a ceramic or a Kevlar type material.

And, are those clutches wet clutches or dry clutches?
Quote
The advantage of an SMT is that it uses a solid coupling (the clutch), which provides a direct connection between engine and transmission and allows 100% of the engine's power to be transmitted to the wheels.


I would think they would have to be some type of wet clutch in order to have cooling provided by the transmission fluid.

I have asked the transmissions shops I work about this very question, but so far they haven't seen enough of these transmissions to actually do tear downs and rebuilds. In the case of these and CVT transmissions, I am told they will simply drop the tranny and send them to a specialty transmission shop for rebuild.

I.e., the business case is, there is not enough traffic to invest in special tools and trained technicians to rebuild either these automated manuals or CVT's.

I have notified the shops that if they do get an AM clutch disk and are able to "borrow" a new one, I intend to send it to a materials analytical group that does this kind of materials analysis, because I too am interested in the answer.

Bottom line is, IMHO, the jury is still out as to the specific composition of the clutch materials used in AM transmissions.

 

[ctechbob]

I think you're confused a little Mola. We're talking about the 5 and 6 speed transmissions. They are a torque converter style transmission with the changing done by clutch packs (internal/wet). They are NOT SMT's even remotely (Audi/VW/Etc.) The only difference between the 5/6 Speed Honda trans and what you are calling a 'step shift' trans is that all of the gear selection is done via clutch packs and that all of the gears are bevel gears on the shafts. There's no planetary/sun gears or brakes/bands. Other than that, they are more similar to a 'step shift' than they are to an SMT/DSG

Once upon a time in the early 90's the Honda 4 speed was more akin to a shifted manual in that it had actual shift forks in the trans, and a torque converter, but this was long before Z1 was a thing, they specified DexIII back then.

I suspect, that when Z1 was created, that it was meant to cover everything new as well as some edge cases of older style transmissions and that when they reformulated it to be more shear stable that they just changed the base oil and left the add pack the same/similar since there wasn't any drawback they could see. (My opinion) The reason that things like Maxlife and the Idemitsu are 'working' without the 'weird' Honda add pack is simply, its not needed anymore. You can hit the viscosity target you need for the solenoids/pump/hydraulics and you've got an add pack with the correct friction properties for the clutches. There are probably not any more 'edge cases' left on the road to worry about and if there are, people are probably driving them to the grave and not caring what's in them.

 

[bulwnkl]

I recall one of Afton's SAE papers I have at home from a decade ago or so which evaluated frictional characteristics of a ‘new' AFT they'd developed vs a range of existing "Asian" fluids. There were 4 such Asian fluids used in the tests, as I recall, and Afton specifically mentioned that one of those specified the use of a different SAE (or was it ISO?) standard clutch disc number. Was that Honda? They didn't say, but it is interesting that one of the Asian ATs used a different friction material than all the others.

 

[MolaKule]

Originally Posted by ctechbob
I think you're confused a little Mola. We're talking about the 5 and 6 speed transmissions. They are a torque converter style transmission with the changing done by clutch packs (internal/wet). They are NOT SMT's even remotely (Audi/VW/Etc.) The only difference between the 5/6 Speed Honda trans and what you are calling a 'step shift' trans is that all of the gear selection is done via clutch packs and that all of the gears are bevel gears on the shafts. There's no planetary/sun gears or brakes/bands. Other than that, they are more similar to a 'step shift' than they are to an SMT/DSG

Once upon a time in the early 90's the Honda 4 speed was more akin to a shifted manual in that it had actual shift forks in the trans, and a torque converter, but this was long before Z1 was a thing, they specified DexIII back then.


I think most of us are aware that conventional Step-Shift transmissions are usually defined as having planetary and sun gears with wet clutches that are hydraulically controlled.

What I was referring to specifically in terms of an AMT, was a "Class" of transmissions that automated the manual shifting operation, with an emphasis on "operation," as in the early Honda's, and gave a modern example of one from, https://www.liveabout.com/dual-clutch-direct-shift-transmission-533860.

That referenced article stated that: "The dual-clutch automatic is a development of the sequential manual transmission (SMT), which is essentially a fully automated manual transmission with a computer-controlled clutch, intended to deliver stick-shift performance with automatic convenience."

The article then went on to describe the advantages of this design due to its solid clutch, verses the fluid coupling arrangement (TC) in conventional Step-Shift transmissions.

So while this topic may involve some differences in semantics, the above article clearly describes a modern version (and certainly not the only one) of an Automated Manual Transmission.

Originally Posted by ctechbob
I suspect, that when Z1 was created, that it was meant to cover everything new as well as some edge cases of older style transmissions and that when they reformulated it to be more shear stable that they just changed the base oil and left the add pack the same/similar since there wasn't any drawback they could see. (My opinion) The reason that things like Maxlife and the Idemitsu are 'working' without the 'weird' Honda add pack is simply, its not needed anymore. You can hit the viscosity target you need for the solenoids/pump/hydraulics and you've got an add pack with the correct friction properties for the clutches. There are probably not any more 'edge cases' left on the road to worry about and if there are, people are probably driving them to the grave and not caring what's in them.


And your viewpoint could very well be correct.

it would be interesting to determine when Honda went from the Dexron III fluid to the Honda Z-1/DW-1 and in what transmissions. What was the technical case or reason for this change? The mystery deepens since there seems to be very little historical data on the web.

Perhaps yourself or clinebarger, or someone else on BITOG may have some old transmission manuals that could shed some light on those earlier Honda transmissions, their fluid requirements, and why and when they changed fluid types.

Now, my concern and warning still stands with respect to using Z-1 or DW-1 in conventional Step-Shift transmissions because of the disparity in chemical signatures. For example, the Friction Modification chemistry in DW-1 is way overboard for use in conventional Step-Shift transmissions.

As I mentioned earlier:
Quote
Not many people are aware, but the presence of calcium and dispersant compounds in Step-Shift transmission fluids have only a secondary task, and this is for minor cleaning and dispercency, respectively, since there are no combustion products present in an AT fluid.

The main purpose of the Calcium, Magnesium and dispersant compounds is to function as one of the many friction modifiers. The other friction modifiers are never shown in low cost analyses but compliment the total friction modification chemistry.

Even the selection of base oils have to be considered as to the effect of overall friction modification. I.e, the base oils, plus any additives, plus the type of VII have to considered in the finished ATF formulation.


The Anti-Wear chemistry in Z-1/DW-1 substitutes what is apparently ZnDTC for the conventional Multi-Functional t-butylphenyl phosphates used in most conventional Step-Shift ATF's. This family of phosphates not only reduces wear, but also modifies the friction coefficients.

I have asked a number of people, that with the DW-1 chemical signature shown, would they honestly now use DW-1 in a conventional Step-Shift transmission and none have answered in the affirmative.

Now Idemitsu does claim their Type H-Plus has: "Advanced anti-wear technology provides maximum protection to gears and bearings."

Let's hope that is the case in terms of long term durability.

 

[ctechbob]

I only pulled the information for the Accord line since I didn't have a lot of time.

I was incorrect about the Dextron III thing, it was Dex II. I think it was my 2003 that said Z1 or DexIII only in an emergency and for temporary use only (yep, see below). Ironically, the 1998+ model years are where the transmissions started getting a little 'iffy' with issues that the older models didn't seem to have. It was thought at the time that Z1 was blended to 'soften up' the gearchanges since Honda was moving on from 'cheap little ecoboxes' to a little more upmarket. Again, that's all speculation and remembering from way back, but that does match up a little with what you've been saying about the Zinc in the formulation doesn't it?

The 1994-1997 Accord with 4 Speed Auto Specs 'Honda Premium Formula'(Whatever that is) or Dex II

The 1998-2002 Starts specifying Z1 "Using a non-Honda ATF can affect shift quality'

In 2003, the owners manual says

'If the level is below the lower mark, add fluid into the tube to bring it to the upper mark. Always use Honda ATF-Z1 (AutomaticTransmission Fluid). If it is not available, you may use a DEXRON III automatic transmission fluid as a temporary replacement. However, continued use can affect shift quality. Have the transmission flushed and refilled with Honda ATF-Z1 as soon as it is convenient.'


Now, what I don't have is anything that says Honda ever back-specced Z1 to the older, pre-1998 cars.

1994-1997

1998-2002

 

[MolaKule]

Thanks for the info and I think this helps us to converge on the past history of these fluids.

If anyone has an old bottle of Honda Premium Formula ATF it would be interesting to see a VOA of it to see how close in formulation it may have been to the old Dexron II.

It seems the more answers we get the more questions that are raised.

Quote
If the level is below the lower mark, add fluid into the tube to bring it to the upper mark. Always use Honda ATF-Z1 (AutomaticTransmission Fluid). If it is not available, you may use a DEXRON III automatic transmission fluid as a temporary replacement. However, continued use can affect shift quality. Have the transmission flushed and refilled with Honda ATF-Z1 as soon as it is convenient.


I can see where the difference in formulation could definitely affect the shift quality since the ZnDTC would create a different COF as opposed to the triphenyl phosphate family of esters in Dexron III.

 

[ctechbob]

I sent off an email to Raybestos just recently. Basically asking 'what makes Honda friction plates so special?. Here is the response:

Thank you for contacting us Shawn,



Please see the answer below from our Tech Support Engineer:



"Regarding Honda Frictions and Honda Transmission Fluid. The Raybestos Powertrain Honda frictions were developed to work in the Honda transmissions just like the Honda Frictions work.

In the past before Raybestos Powertrain developed the GPX Honda Frictions there was no aftermarket solution that worked.

If you used a different fluid in a Honda transmission it would shift different.

If you used a different fiction material in a Honda transmission it would shift different.

In most cases the different shifting would cause unpleasant results.

Raybestos Powertrain was the first company to provide a friction material (GPX) that would feel just like the Honda friction material in a Honda transmission using Honda fluid.

If you were to use a different fluid in a Honda transmission with the GPX friction material, you can expect the same similar shift feel as if the transmission had Honda frictions and the same different fluid.

It appears the transmission was designed with not only the friction material in mind, it also included the transmission fluid as well."

Thank you,

Nick Truncone
Marketing Manager
Gearbox Holdings Inc. / Raybestos Powertrain LLC.
711 Tech Drive | Crawfordsville, IN 47933