Modern Replacement for Type A ATF
- Thread starter jacobs
- Start date
- Status
AMSOIL's Super Shift is the only modern fluid that is for Ford Type F that I'm aware of.
https://www.amsoil.com/shop/by-prod...ransmission-fluid-sae-10w/?code=ARTQT-EA
https://www.amsoil.com/shop/by-prod...ransmission-fluid-sae-10w/?code=ARTQT-EA
Type F is for Ford, Type A is GM.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
Originally Posted by WagonWheel
Type F is for Ford, Type A is GM.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
What's not backwards compatible? dexron VI is the licensed replacement fluid (per GM) for those applications that specify dexron III (or previous), and would be appropriate for Type A.
Type F is for Ford, Type A is GM.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
What's not backwards compatible? dexron VI is the licensed replacement fluid (per GM) for those applications that specify dexron III (or previous), and would be appropriate for Type A.
Best I can tell from my brief lunch break research, Dex/Merc is compatible and has better oxidation control.
MolaKule
Staff member
The modern replacement fluid is indeed Dexron VI:
Quote
From a GM tech bulletin:
Although DEXRON-VI (fig. 1) was introduced into production starting with 2006 model year vehicles (see bulletin 04-07-30-037D), there are still some misunderstandings about it. Here are some facts to help clear up these misunderstandings.
Since GM introduced the first service-fill specification for automatic transmission fluid (ATF) in 1949, it has been necessary periodically to upgrade the specification as part of a continuous improvement strategy. The upgrading process ensures that available service fill fluids are of an appropriate quality for use in transmissions that have been designed around the improved factory fill fluid performance.
IMPORTANT: As with previous upgrades, DEXRON-VI fluids are designed to be backward compatible with earlier transmission hardware. But more important, earlier type fluids are NOT FORWARD COMPATIBLE with transmissions that were designed to use DEXRON-VI.
DEXRON-VI can be used in any proportion in past model vehicles equipped with an automatic transmission, in place of DEXRON-III (for instance, topping off the fluid in the event of a repair or fluid change). DEXRON-VI is also compatible with any former version of DEXRON for use in automatic transmissions.
TIP: Simply topping off the fluid is adequate, but a full drain and replacement is preferred, to obtain the full benefit.
Quote
From a GM tech bulletin:
Although DEXRON-VI (fig. 1) was introduced into production starting with 2006 model year vehicles (see bulletin 04-07-30-037D), there are still some misunderstandings about it. Here are some facts to help clear up these misunderstandings.
Since GM introduced the first service-fill specification for automatic transmission fluid (ATF) in 1949, it has been necessary periodically to upgrade the specification as part of a continuous improvement strategy. The upgrading process ensures that available service fill fluids are of an appropriate quality for use in transmissions that have been designed around the improved factory fill fluid performance.
IMPORTANT: As with previous upgrades, DEXRON-VI fluids are designed to be backward compatible with earlier transmission hardware. But more important, earlier type fluids are NOT FORWARD COMPATIBLE with transmissions that were designed to use DEXRON-VI.
DEXRON-VI can be used in any proportion in past model vehicles equipped with an automatic transmission, in place of DEXRON-III (for instance, topping off the fluid in the event of a repair or fluid change). DEXRON-VI is also compatible with any former version of DEXRON for use in automatic transmissions.
TIP: Simply topping off the fluid is adequate, but a full drain and replacement is preferred, to obtain the full benefit.
MolaKule
Staff member
Originally Posted by Red91
Best I can tell from my brief lunch break research, Dex/Merc is compatible and has better oxidation control.
Dexron VI is the most stable of the Dexron fluids to date.
Quote
Here are some facts and specifications about these Dexron fluids:
Dex III/Mercon type fluids: Max cSt 7.5; shears down to 4.2 cSt under standard tests;
GM Dexron VI: Starting viscosity cannot be > than 6.4 cSt; cannot shear down to less than 5.5 cST under standard tests;
Mobil 1 Dexron VI: Starting viscosity - 5.83 cSt, cannot shear down to less than 5.5 cST under standard tests;
MaxLife ATF: Starting viscosity - 5.91 cSt, cannot shear down to less than 5.5 cST under standard tests;
Redline D6 ATF: Starting viscosity - 6.4 cSt, cannot shear down to less than 6.1 cST under standard tests.
Shear testing is done using four tests; the Fuel Injector Shear Stability test, the Sonic shear test, the DEXRON®-III Cycling test and the KRL test.
The KRL tests have been shown to provide the better accelerated shear tests, in which all of the above fluids have been subjected.
One other important specification is the Brookfield viscosity at -40C for the Dexron VI has to be at least 5000 units lower than the Dexron III(H) or Dex/Merc.
This means Dexron VI has better cold temperature operation than does the Dexron III(H) or Dex/Merc.
-------------------------------------------------------------------------------------------------------------------------------
Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100C
exron III(H) 7.3 cSt, Dexron VI - 5.9 cSt
Shear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
Best I can tell from my brief lunch break research, Dex/Merc is compatible and has better oxidation control.
Dexron VI is the most stable of the Dexron fluids to date.
Quote
Here are some facts and specifications about these Dexron fluids:
Dex III/Mercon type fluids: Max cSt 7.5; shears down to 4.2 cSt under standard tests;
GM Dexron VI: Starting viscosity cannot be > than 6.4 cSt; cannot shear down to less than 5.5 cST under standard tests;
Mobil 1 Dexron VI: Starting viscosity - 5.83 cSt, cannot shear down to less than 5.5 cST under standard tests;
MaxLife ATF: Starting viscosity - 5.91 cSt, cannot shear down to less than 5.5 cST under standard tests;
Redline D6 ATF: Starting viscosity - 6.4 cSt, cannot shear down to less than 6.1 cST under standard tests.
Shear testing is done using four tests; the Fuel Injector Shear Stability test, the Sonic shear test, the DEXRON®-III Cycling test and the KRL test.
The KRL tests have been shown to provide the better accelerated shear tests, in which all of the above fluids have been subjected.
One other important specification is the Brookfield viscosity at -40C for the Dexron VI has to be at least 5000 units lower than the Dexron III(H) or Dex/Merc.
This means Dexron VI has better cold temperature operation than does the Dexron III(H) or Dex/Merc.
-------------------------------------------------------------------------------------------------------------------------------
Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100C
exron III(H) 7.3 cSt, Dexron VI - 5.9 cStShear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
Last edited:
OK I miss read it big time. I saw type and my head just read it as type F.
How can it be DexVI a substitute for ATF A...I have Tomos automatic mofa....wich specs ATF A in its transmission....it shifts ok with it....but if I switch to dex III in it it shifts like garbage...
So there has to be different friction characteristics between different ATFs...
So there has to be different friction characteristics between different ATFs...
Garbage? Well some people just have problems despite their best effort, you know?
Well....it engine has only 2gears....with ATF A it shifts between them easily....if you fill it with ATF III it doesn't want to engage into 2nd for quite a while...
The change is very noticable...that clutch in 2nd gear slips a lot...that shows me that friction characteristics of ATF III are way different...
The change is very noticable...that clutch in 2nd gear slips a lot...that shows me that friction characteristics of ATF III are way different...
Originally Posted by kschachn
Originally Posted by WagonWheel
Type F is for Ford, Type A is GM.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
What's not backwards compatible? dexron VI is the licensed replacement fluid (per GM) for those applications that specify dexron III (or previous), and would be appropriate for Type A.
Oh sorry, you're right. I misread the Wiki and thought it was acceoonly if Dex II/II was spec'd
This link (wiki reference) seems to explain why Dex 6 is acceptable for Type A and later.
https://web.archive.org/web/20101220203431/http://www.gm.com/experience/technology/gmpowertrain/transmissions/DEXRON_VI_Service_Fill_Release_30NO07.doc
"All DEXRON®-III licenses expire at the end of 2006 and will not be renewed. Beyond that date GM will only support the use of DEXRON®-VI fluids for use in Hydra-Matic transmissions. Fluids sold in the market after that date bearing claims such as "suitable for use in DEXRON®-III applications" or similar wording should be avoided. DEXRON®-VI licensed fluids are fully backward compatible and can be used in all applications covered by earlier GM ATF specifications."
Originally Posted by WagonWheel
Type F is for Ford, Type A is GM.
According to the DEXRON wikipedia page:
https://en.wikipedia.org/wiki/DEXRON
Which is mostly maintained by Weber State Prof. John Kelly (see his detailed YouTube vids), the latest replacement for Type A is DEXRON III(H). The catch is there is no official valid license for this fluid anymore. I'd be wary of any fluid that claims compatibility to newer DEXRON standards since they are not backwards compatible with Dex III and earlier.
What's not backwards compatible? dexron VI is the licensed replacement fluid (per GM) for those applications that specify dexron III (or previous), and would be appropriate for Type A.
Oh sorry, you're right. I misread the Wiki and thought it was acceoonly if Dex II/II was spec'd
This link (wiki reference) seems to explain why Dex 6 is acceptable for Type A and later.
https://web.archive.org/web/20101220203431/http://www.gm.com/experience/technology/gmpowertrain/transmissions/DEXRON_VI_Service_Fill_Release_30NO07.doc
"All DEXRON®-III licenses expire at the end of 2006 and will not be renewed. Beyond that date GM will only support the use of DEXRON®-VI fluids for use in Hydra-Matic transmissions. Fluids sold in the market after that date bearing claims such as "suitable for use in DEXRON®-III applications" or similar wording should be avoided. DEXRON®-VI licensed fluids are fully backward compatible and can be used in all applications covered by earlier GM ATF specifications."
Last edited:
I just meant as compared to type A. I didn't have time to check Dex 6 compatibility and benefits. I'm glad you posted the info though, because i really couldn't find a definitive answer.
One of the shady brands still sells Type-A
Accel Type A
Accel Type A
Warren unilube also markets type a under the Warren brand. If I'm not mistaken, accel is a Warren distribution product. I'd be interested to see if they're up to par for type a, just because. Seems like the answer overall is run Dex VI.
Just out of curiosity, what is the MODERN application of Type A and Type F these days, assuming you are not putting it in an antique?
Originally Posted by PandaBear
Just out of curiosity, what is the MODERN application of Type A and Type F these days, assuming you are not putting it in an antique?
There is no replacement for type F and that is why it's still on the shelves. Type F is used in older Ford transmissions and power steering units. My '93 F150 requires type F in the PS. Don't ask how I found that out!
Type A became Dexron and so on so Dexron VI should be acceptable. Mercon V would also work and would be my choice.
Just out of curiosity, what is the MODERN application of Type A and Type F these days, assuming you are not putting it in an antique?
There is no replacement for type F and that is why it's still on the shelves. Type F is used in older Ford transmissions and power steering units. My '93 F150 requires type F in the PS. Don't ask how I found that out!
Type A became Dexron and so on so Dexron VI should be acceptable. Mercon V would also work and would be my choice.
Last edited:
- Status
