Three ATF's Analyzed

[MolaKule]

Originally Posted by 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

I think it still stands that in the Honda AMT's they needed a mix of chemistries to not only obtain a specific Friction Coefficient (as seen by the Calcium and Magnesium levels), but the original DW-1 Honda zinc levels also indicate they needed a certain level of Anti-Wear agents. It is most interesting to see that many of these Manf. responses have continued to ignore or to address the zinc dialkyldithiocarbamate levels in the original Honda DW-1.

 

[nthach]

Originally Posted by ctechbob

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. .

Well since a Honda AT except the new 10-speed unit used in the Odyssey that's closer to a conventional planetary-based AT is built like a manual and has similar powerflow between the shafts, they want more Zn since there is still sliding wear within the geartrain, especially with the manual forward/reverse fork and any sliding within the clutch packs or the gears on their shafts. https://www.youtube.com/watch?v=bYGnMM5rL9g - it's a teardown of a Honda 6-speed.

 

[Parrajl1984]

Originally Posted by ctechbob

"Once more, we would like to reaffirm that the Idemitsu ATF Type H Plus uses a different additive package than DW-1—however, this has no bearing or impact on the formulation's ability to meet the prescribed performance properties for this particular transmission." They didn't say why it is different, just that it is.

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

they meet the fluid properties according to the chart. Zinc and phosphorus ratio? Now your taking it to the basic elements. I don’t know man. I’m thinking it’s a good substitute. You guys are just Honda freaks. I’m pretty sure this stuff is engineered for what it’s made to do. Wear and tare is inevitable.

 

[Parrajl1984]

I’m pretty sure we are overthinking this. If a Honda lasts that long, At that point you should probably buy another car. Your transmission is going to run like new but the rest of the car is falling apart. Lol. Just cause you stuck to genuine Honda atf dw1.

 

[2EHA]

[While the friction modification mix in modern Multi-vehicle fluids such as MaxLife has a broad spectrum of application, I also question the coverage or applicability to ATF +4 fluids.

Is ATF+4 more or less compatible for transmissions designed around a dexron type fluid but not the other way around due to the unique friction requirements of 90s Mopar transmissions?

The MB NAG1 started out life with the usual dexron copypaste and later a “dexron iii technology” early LV fluid. When Chrysler decided to use it in Hemi applications with identical german made transmissions, they got specced ATF+4 without issue.

 

[MolaKule]

The answer to the first question is no, since ATF+4 has a different frictional characteristics than do the Dexron series.

While the W5A580 is a HD transmission, the TCC needed the frictional characteristics of the ATF+4.

 

[2EHA]

While the W5A580 is a HD transmission, the TCC needed the frictional characteristics of the ATF+4.

CRD Grand Cherokees called for ATF+4 and had MB built transmissions coupled to an MB built engine, all presumably minimally modified for the task. Is it really a design change to the torque converter clutch that requires heavily friction modified ATF+4 to be used or is it simply indifferent to the two different fluids in normal usage?

Just remembered that FCA approves ATF+4 for all legacy applications with dexron based fluids (7176D, ATF+2, etc) which leads me to believe it’s somewhat backwards compatible.

 

[MolaKule]

CRD Grand Cherokees called for ATF+4 and had MB built transmissions coupled to an MB built engine, all presumably minimally modified for the task. Is it really a design change to the torque converter clutch that requires heavily friction modified ATF+4 to be used or is it simply indifferent to the two different fluids in normal usage?

Just remembered that FCA approves ATF+4 for all legacy applications with dexron based fluids (7176D, ATF+2, etc) which leads me to believe it’s somewhat backwards compatible.

What do you mean when you say "Dexron-based" fluids?

7176D, ATF+2, ATF+3, ATF+4 etc are not Dexron-based fluids.

The size (diameter) of the clutch packs, the clutch disk composition, the applied engagement pressure, shift feel, and the timing (programming) of engagement-disengagement all determine the required friction coefficient.

 

[Hogwash]

Very interesting thread. I just read every post. Admittedly 99% when over my head....and most of the discussion seems to be focused on Honda.

But for those of us who have used Maxlife in Toyotas for some time....are there implications that perhaps we're on borrowed time?

Someone explain in simple knuckle dragging layman's terms

 

[ctechbob]

Very interesting thread. I just read every post. Admittedly 99% when over my head....and most of the discussion seems to be focused on Honda.

But for those of us who have used Maxlife in Toyotas for some time....are there implications that perhaps we're on borrowed time?

Someone explain in simple knuckle dragging layman's terms

Probably not. (Hurt your Toyota that is)

This thread was started from a debate several of us were having regarding several of the 'use where DW1/Z1 fluid is recommended' (IE Idemitsu, Aisin, Maxlife, ETC). The discussion started after VOA's showed that DW1 contained a fairly unique additive package that none of the other fluids came close to. What it boiled down to in the end was that the other brands were using different chemistries to meet the performance aspects of real deal 'Honda/Acura' DW1. What that means in the grand scheme of things as far as wear prevention over the long haul, none of us are completely sure.

The only thing most of us are sure of is:

DW1 is a unique fluid.

Many people use alternate fluids in 'DW1 Only' transmissions.

Most people that do, are fairly happy with the performance.

Some people notice some changes with the different fluids.

Lots and lots of people use MaxLife in many different models and makes and are happy.

No one has had a Honda/Acura transmission grenade while using the aftermarket fluids that can pin the failure to that fluid.

As for your Toyota. Not a clue, you'd have to find some VOA's of OEM Toyota fluid and go from there.