Tranny Fluid question

[toolmanmike]

Here's a post from FABO. Dexron III would be my choice.

Technical differences between F and the others is friction modifiers.
All of the Dex/Merc and related ATFs are friction modified. The modified ATF's change the way the clutches and bands grab and hold. All things being equal, the clutches and bands will grab quicker and harder with an unmodified ATF than a modified ATF. (They also may effect the release)

Type F. It's in a category of its own.
The only unmodified ATF with a dynamic coefficient that increases as clutches and bands lock up - resulting in firmer shifts.
If that's what you need, great. Drawback is that the fluid doesn't hold up as long. Result is often what @Duster346 has observed.

Dexron and Mercon - a chronology.
Gleanings from the web which appear to be more substantial than wild rumors, but you've been warned.
Dexron II 1973 - 1987
Dexron IIe was for electronic controls & had extra cleaning agents.
Mercon 1992- Contained less wax than Dexron
Dexron III c.1993 - Similar to Mercon. Lower low temperature viscosity than earlier versions of Dexron. Said to have better oxidation resistance and improved seal life.

ATF+3, ATF+4. Similar to Dexron but formulated specifically for
Chrysler transmission control modules. All of the manufacturer spec
sheets I found on-line seemed to agree - NOT recommended for DEX 3
applications.

Dexron VI. This was GM's latest standard (c 2008). By definition, Dex VI is fully synthetic and has the lowest low temperature viscosity. That
could be great for street and the first autocross run of the day. Several manufacturers specifically list it as backward compatible to Dex III and Dex II. I've used one of them. It's expensive, and if you have lingering doubts about using it, that cynicism seems reasonable to me.

I've used Dex II and III, Type F, ATF+, Dex VI at one time or another in my own 727 and 904s. The only one that I was really unhappy with how it seemed to effect the shifting was a ATF+3/+4.

edit: The current wikipedia page on Dexron seems very thorough. DEXRON - Wikipedia
and according to the following thread, is maintained by a Weber State prof John Kelly.
https://bobistheoilguy.com/forums/threads/modern-replacement-for-type-a-atf.311678/

Last edited: Aug 26, 2023

 

[kiwigtx]

As a side note.... my buddy Cliff collects waste tranny fluid, sieves it and runs an old Toyota Corolla diesel wagon on it. It runs cleaner than diesel and doesn't suffer any loss of power. The car doesn't smoke either.
I reckon he could run that thing on anything but water.....even hawk tuah juice once it's up and running.

 

[toolmanmike]

As a side note.... my buddy Cliff collects waste tranny fluid, sieves it and runs an old Toyota Corolla diesel wagon on it. It runs cleaner than diesel and doesn't suffer any loss of power. The car doesn't smoke either.
I reckon he could run that thing on anything but water.....even hawk tuah juice once it's up and running.

The older diesels like some lubrication running through the pumps and injectors. They took sulfur out and killed the lube. My old 88 with a GM 6.5 loved some ATF mixed in with the fuel with every tank.

 

[khryslerkid]

Here's a post from FABO. Dexron III would be my choice.

Technical differences between F and the others is friction modifiers.
All of the Dex/Merc and related ATFs are friction modified. The modified ATF's change the way the clutches and bands grab and hold. All things being equal, the clutches and bands will grab quicker and harder with an unmodified ATF than a modified ATF. (They also may effect the release)

Type F. It's in a category of its own.
The only unmodified ATF with a dynamic coefficient that increases as clutches and bands lock up - resulting in firmer shifts.
If that's what you need, great. Drawback is that the fluid doesn't hold up as long. Result is often what @Duster346 has observed.

Dexron and Mercon - a chronology.
Gleanings from the web which appear to be more substantial than wild rumors, but you've been warned.
Dexron II 1973 - 1987
Dexron IIe was for electronic controls & had extra cleaning agents.
Mercon 1992- Contained less wax than Dexron
Dexron III c.1993 - Similar to Mercon. Lower low temperature viscosity than earlier versions of Dexron. Said to have better oxidation resistance and improved seal life.

ATF+3, ATF+4. Similar to Dexron but formulated specifically for
Chrysler transmission control modules. All of the manufacturer spec
sheets I found on-line seemed to agree - NOT recommended for DEX 3
applications.

Dexron VI. This was GM's latest standard (c 2008). By definition, Dex VI is fully synthetic and has the lowest low temperature viscosity. That
could be great for street and the first autocross run of the day. Several manufacturers specifically list it as backward compatible to Dex III and Dex II. I've used one of them. It's expensive, and if you have lingering doubts about using it, that cynicism seems reasonable to me.

I've used Dex II and III, Type F, ATF+, Dex VI at one time or another in my own 727 and 904s. The only one that I was really unhappy with how it seemed to effect the shifting was a ATF+3/+4.

edit: The current wikipedia page on Dexron seems very thorough. DEXRON - Wikipedia
and according to the following thread, is maintained by a Weber State prof John Kelly.
https://bobistheoilguy.com/forums/threads/modern-replacement-for-type-a-atf.311678/

Last edited: Aug 26, 2023

Do you have a link to the FABO thread?

 

[forphorty]

Dexron III - stupid spellchecker on my phone.

I liked your Detroit III answer better. I thought you were making a funny.

 

[kiwigtx]

I liked your Detroit III answer better. I thought you were making a funny.

Thank you. it did come out that way.....usually I would do that on purpose.

 

[not so famous bob]

SHURE!!!!! Didn't he build a dam????

He was mostly responsible for the 426 hemi being built ...

 

[VANDAN]

Kind of off topic here, but what fluid came in, or is used in '05 Ram Cummins Autos ? Did they come from Factory with the Synthetic ATF+4 ? I've been wanting to add a deeper pan, so I'd like to match the fluid on the change...

 

[1967coronet]

what exactly is the difference?

Oh Bob........ we have a technical question.

 

[33 IMP]

Kind of off topic here, but what fluid came in, or is used in '05 Ram Cummins Autos ? Did they come from Factory with the Synthetic ATF+4 ? I've been wanting to add a deeper pan, so I'd like to match the fluid on the change...

View attachment 1711490

Yes, ATF+4 full syn, according to Googles AI.

 

[khryslerkid]

SHURE!!!!! Didn't he build a dam????

Know for inventing the Hoover vacuum cleaner. It really sucked!

 

[33 IMP]

Know for inventing the Hoover vacuum cleaner. It really sucked!

The president invented the vacuum cleaner? Before or after the depression?

 

[33 IMP]

The older diesels like some lubrication running through the pumps and injectors. They took sulfur out and killed the lube. My old 88 with a GM 6.5 loved some ATF mixed in with the fuel with every tank.

@toolmanmike i'm open to new ideas.
How much tranny fluid to how many gallons of diesel?

 

[451Mopar]

Kind of off topic here, but what fluid came in, or is used in '05 Ram Cummins Autos ? Did they come from Factory with the Synthetic ATF+4 ? I've been wanting to add a deeper pan, so I'd like to match the fluid on the change...

View attachment 1711490

Yes, the ATF+4 is factory for the 2005 48RE transmission.
My 2005 Ram 3500 has the large ATS trans pan, and draining the fluid will almost fill a 5-gallon bucket.

 

[Kern Dog]

Type of fluid- any, except type F.

What's wrong with type F? It's what I'm using. Gives a firmer shift if that's what you like.

After 59 years of doing 727s I have found that F was developed for Furd transmissions and works for the Furd because it has a friction modifier and that helped Furd to combat clutch slippage. F is a bit short on lubrication properties. Any type A will work just fine and has the better lube properties.
But I'm kinda new to this and willing to learn.

I run Type F as recommended by a well known Mopar trans builder, zero issues…

B.S. , been running type F for around 50 yrs. , ran it in a hemi super stocker for 14 yrs. , never had problem with it , have it in my 505'' 68 fastback now , been in it for about 12ish yrs ...
Tom Hoover was asked this question at a drag seminar in OKC way back , he recommended type F ....

do you even know who Tom Hoover was ??

@toolmanmike i'm open to new ideas.
How much tranny fluid to how many gallons of diesel?

I know a guy that dumped ATF in his 93 Cummins D-250. He'd put 2 gallons of ATF per tank if he had ATF sitting around. No catalytic converters on those trucks, no DEF either.

 

[kiwigtx]

The president invented the vacuum cleaner? Before or after the depression?

He was busy at the time .... F.B.I. - Fairly Big Invention.

Using his own name initially, he thought it was a great way to suck up the criminals.

 

[cosgig]

I remember awhile back, they had that blue trans fluid out that was supposed to be the ****. I had just had my trans rebuilt with the a995 planetary and they used my old input shaft, so it ripped the teeth off the shaft. Took it back to my trans guy, and when he saw that blue fluid in it he just laughed. I asked him about it and he matter of factly said thst I wasted my money, all trans fluid is basically the same, and the 727/904 will run on anything. I use type F if I can find it now, or ATF-4. No problems in any of my cars after all these years.

 

[33 IMP]

I always use type f cause it's supposed to give firmer positive shifts. That is exactly what I want. I like a nice stiffy shift, nothing limp or soft.

 

[cosgig]

I always use type f cause it's supposed to give firmer positive shifts. That is exactly what I want. I like a nice stiffy shift, nothing limp or soft.

Oh Lord, are we talking about trannies, or trannys here? ;-)

 

[Black_Sheep]

I remember awhile back, they had that blue trans fluid out that was supposed to be the ****. I had just had my trans rebuilt with the a995 planetary and they used my old input shaft, so it ripped the teeth off the shaft. Took it back to my trans guy, and when he saw that blue fluid in it he just laughed. I asked him about it and he matter of factly said thst I wasted my money, all trans fluid is basically the same, and the 727/904 will run on anything. I use type F if I can find it now, or ATF-4. No problems in any of my cars after all these years.

B&M Trik Shift is blue, allegedly it’s Type F with blue dye…