4L80E. Any Recommendations? Dex VI?
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Dex 3 is history, has been for a long time now.. GM issued a TSB stating DEX 6 is to be used to replace Dex 3 where it is specified in their transmissions. Not Chrysler's ATF 4, if it were better, it would have been suggested . I would certainly trust the engineers at GM over your suggestion simply based on viscosity. You have no idea the friction characteristics of DEX 3,6 or ATF 4. I used DEX 6 in my old GM transmission and it shifted perfectly hot or cold. So why would someone follow your suggestion?
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Originally Posted by Lubener
Originally Posted by zeng
Originally Posted by Smith5361
Originally Posted by zeng
Originally Posted by Smith5361
zeng said:
Why not use Pennzoil Platinum High Mileage ATF? Fully synthetic formation with Dex III specs!
https://www.pepboys.com/pennzoil-platinum-high-mileage-atf-quart/product/1162204?quantity=1
https://www.pennzoil.com/en_us/prod...LzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fdXM=
PPHM ATF PDS
Or if you don't like Pennzoil, Mobil 1 ATF is also fully synthetic with Dex III viscosity but at a higher price point.
https://www.pepboys.com/mobil-1-syn...fluid-1-quart/product/9008702?quantity=1
https://mobiloil.com/en/automatic-transmission-fluid/synthetic-atf
https://www.pepboys.com/pennzoil-platinum-high-mileage-atf-quart/product/1162204?quantity=1
https://www.pennzoil.com/en_us/prod...LzIwMTZuZXdzbGV0dGVyLz9sb2NhbGU9ZW5fdXM=
PPHM ATF PDS
Or if you don't like Pennzoil, Mobil 1 ATF is also fully synthetic with Dex III viscosity but at a higher price point.
https://www.pepboys.com/mobil-1-syn...fluid-1-quart/product/9008702?quantity=1
https://mobiloil.com/en/automatic-transmission-fluid/synthetic-atf
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Originally Posted by dave1251
This is absurd reasoning funny man. GM would never endorse a Chrysler product.
Exactly , when non-science paremeters takes precedence over science parameters in arguing over science .
On the issue of science, or facts :
This is absurd reasoning funny man. GM would never endorse a Chrysler product.
Exactly , when non-science paremeters takes precedence over science parameters in arguing over science .
On the issue of science, or facts :
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Yes, but what of the friction characteristics?
That's why I'd use PP HM ATF or Mobil 1 ATF in such a transmission personally. Both are formulated for Dex III applications, and Mobil 1 ATF was around before Dex VI came out IIRC.
Royal Purple Max ATF would be a third alternative.
http://www.royalpurpleconsumer.com/products/max-atf-automatic-transmission-fluid/
Royal Purple Max ATF would be a third alternative.
http://www.royalpurpleconsumer.com/products/max-atf-automatic-transmission-fluid/
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Originally Posted by Hemispheres
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
Which ATF are dexron 4 licensed?
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
Which ATF are dexron 4 licensed?
Originally Posted by Hemispheres
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
If it is slipping due to wear unless your dropping the pan every 5K and changing Dex III it will slip on it also.
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
If it is slipping due to wear unless your dropping the pan every 5K and changing Dex III it will slip on it also.
Originally Posted by Hemispheres
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
The Pressure Regulating System can/does react to pressure losses, Even with the 4L80E having a fixed displacement pump.....It's large enough (capacity wise) to overcome any viscosity related pressure reduction.
Another oddity exclusive to the 4L80E & only a handful of other units......
IF the pump/boost system is worn enough.......The Torque Converter Clutch will drag at idle speeds, Causing stalling issues HOT long before burning frictions or "slipping" will occur from low line pressure.
Just about EVERY TCC requires adequate pressure to keep it in the OFF/Not Applied state, Units such as the 4L80E use a scheme that puts a priority to the clutch packs OVER the TCC & Cooler feed circuits IF the pumps capacity is maxed-out.
Units like a 4L60E for example.....Have a TCC Off/Cooler bypass circuit that will rob vital pressure with the pump capacity maxed, Though this unit has a Variable Displacement Pump.
I have never personally seen the lower starting viscosity of Dexron VI EVER cause a pressure issue that wouldn't still be present & just as detrimental when using Dexron III.
This thread is FULL of misinformation!
Its a toss up. Depending on wear and type of fluid used Dex 6 can cause slipping due to being slightly thinner than Dex 4.
The Pressure Regulating System can/does react to pressure losses, Even with the 4L80E having a fixed displacement pump.....It's large enough (capacity wise) to overcome any viscosity related pressure reduction.
Another oddity exclusive to the 4L80E & only a handful of other units......
IF the pump/boost system is worn enough.......The Torque Converter Clutch will drag at idle speeds, Causing stalling issues HOT long before burning frictions or "slipping" will occur from low line pressure.
Just about EVERY TCC requires adequate pressure to keep it in the OFF/Not Applied state, Units such as the 4L80E use a scheme that puts a priority to the clutch packs OVER the TCC & Cooler feed circuits IF the pumps capacity is maxed-out.
Units like a 4L60E for example.....Have a TCC Off/Cooler bypass circuit that will rob vital pressure with the pump capacity maxed, Though this unit has a Variable Displacement Pump.
I have never personally seen the lower starting viscosity of Dexron VI EVER cause a pressure issue that wouldn't still be present & just as detrimental when using Dexron III.
This thread is FULL of misinformation!
MolaKule
Staff member
Originally Posted by clinebarger
...I have never personally seen the lower starting viscosity of Dexron VI EVER cause a pressure issue that wouldn't still be present & just as detrimental when using Dexron III.
This thread is FULL of misinformation!
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.
...I have never personally seen the lower starting viscosity of Dexron VI EVER cause a pressure issue that wouldn't still be present & just as detrimental when using Dexron III.
This thread is FULL of misinformation!
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.
Originally Posted by zeng
Originally Posted by dave1251
This is absurd reasoning funny man. GM would never endorse a Chrysler product.
Exactly , when non-science paremeters takes precedence over science parameters in arguing over science .
On the issue of science, or facts :
Dex and ATF +4 are not similar fluids did you make this consideration in the name of science?
Originally Posted by dave1251
This is absurd reasoning funny man. GM would never endorse a Chrysler product.
Exactly , when non-science paremeters takes precedence over science parameters in arguing over science .
On the issue of science, or facts :
Dex and ATF +4 are not similar fluids did you make this consideration in the name of science?
Originally Posted by dave1251
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
Originally Posted by PiperOne
Originally Posted by dave1251
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
When was the fluid changed. All Dexos VI are group III. And if you read the Dexos VI certification specs the same rigorous specs are outlined including useage requirements.
Originally Posted by dave1251
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
When was the fluid changed. All Dexos VI are group III. And if you read the Dexos VI certification specs the same rigorous specs are outlined including useage requirements.
Originally Posted by PiperOne
Originally Posted by dave1251
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
I assume you did a UOA on the factory fill then you did one on the replaced fluid thus concluded with the extra debris in the UOA from the factory you have have concluded the factory AC Delco is inferior?
Originally Posted by dave1251
Originally Posted by PiperOne
Dex VI is fine...have a 4L85 here with over 450,000 on it. However...all Dex VI is not created equal....in fact the AC Delco stuff when we used it returned terrible samples. Switched to Chevron/Havoline Full Syn DexVI and problems went away immediately. Dex VI add packs are very similar to meet the licence spec...but the base oil varies. If you can keep the fluid under 170F it will handle anything you throw at it with ease.
The same rigorous spec is met.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3007594/1
OK..great..same spec...why did the Delco break down (per the sample results from the lab) and result in higher amounts of stuff in the pan ? Input specs are one thing...but what happens with use matters more to me...I stand by my original statement.
I assume you did a UOA on the factory fill then you did one on the replaced fluid thus concluded with the extra debris in the UOA from the factory you have have concluded the factory AC Delco is inferior?
I have a 98 K3500 with the 7.4L/4L80E. I bought this truck with 94,000 miles on it back in 2007 and changed the transmission fluid shortly after and used Supertech HM fluid. I did another drop and refill after that with the same fluid. The truck now has about 117,000 on it and still shifts fine. When it gets really cold out or the truck sits for an extended period of time without being driven, it seems to take a little longer to shift into gear on the initial shift from park to OD but that goes away when it warms up.
I've thought about going to Dextron VI on my next change but am leery based on some of the things I've read. If you try it in your truck, I will be interested in how it does.
I've thought about going to Dextron VI on my next change but am leery based on some of the things I've read. If you try it in your truck, I will be interested in how it does.
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