Trans fluid?

Valvoline DEX/MERC. Name brand always tests. Better, you are paying for the additives.

Type F is a farce, the worst lubricating qualities of any ATF.
 
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A long time ago, back when we had to shoo the dinosaurs off the race track, I was told by a Chrysler engineer (Bill Hancock) that the difference with type-F versus Dexron was that there were more "friction modifiers" in the type-F. This made for less slippage in the clutches, but made for a harsher, faster shift.

He had a heavy southern drawl and explained how they wanted "Mommy's Imperial" not shifting very hard, but for a performance car, it was just fine and would actually make everything last just a little longer because there was less slippage and less heat.

So, in answer to the OP's question, I use Dexron III/Mecron fluid as I can get that about anywhere and type-F is a little harder to find. The real answer for me is to fix the leaks and not use so much fluid, but that's another story.
 
Type F if you want firmer shifts.
And why are the shifts former? Because it doesn’t lubricate well, it grabs because it’s not slippery. True story. I know many folks use type F with no problems, And that’s great. But I’m telling you the truth about what you are getting with the F.
 
Type F
Dexron3/ Mercon is okay and backwards compatible. It is a semi synthetic and was factory fill in transmissions that still used bands, 518, 618, 700r4/4L60 etc. ATF +4 is factory fill for transmissions without bands, yes it will work. It is a full synthetic, designed for longevity and fuel mileage and to work with plate clutches primarily (converter lock up, and many different clutch pack combos, all rotating in the same direction but at different speeds). The second gear band on a 727/904 is the hardest working piece in the trans. It has to grab and stop spinning completely the forward drum. WOT shifts from 1-2 anywhere from 4500-6000 in some cases. So ask yourself so you really want to put your kickdown band through the misery of extra slippery fluid? Your call, but if it's is not F or Dexron 3, please keep your junk away from my car.
 
Walmart’s dex/merc here as well, with no problems the last several years.

Also used +4 as well in the past. Stuff must be liquid gold though the way it is priced....
 
I used Walmart's Type F before rebuilding the tranny 19 mos ago, and Type F + Lucas was the ONLY reason that worn out setup drove at all, in the opinion of the shop I hired for the rebuild. Now I'm running Castrol's Transmax DEX/MERC, which was what the shop filled it with. It performs nicely, though with a little slip in 1st gear. I like that when at intersections with SHORT red lights where I can idle at 500 rpm and not strain my brakes or the tranny. I climb the 50 degree slopes of hillside caliche driveways sans trouble though. The low-reverse band might need a little tightening this Fall......

The fricative modifiers in Type F do make for snappier shifting. I'll re-introduce Type F when I change the fluid, which shouldn't be for a long time. I don't lose a DROP of fluid yet, thank God and Hermann's Transmissions.
 
Your torqueflight wasn’t designed for type F, and it still doesn’t need it to work great for years.

Type F is a ford band aid, your torqueflight doesn’t need it and it won’t work any better.

How many second gear band failures are there in TF727 and 904? Almost zero. It’s the high gear clutch pack that’s the problem.

There are no trans failures from type F, dexron, or ATF+4, it all works fine. Some lubricate better. Pick your poison. All this bickering and they still keep on working.
 
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thanks for the incite guys.
the car has 86K original miles when it was stored in 1974. Pan gasket is seeping fluid so I will drop the pan, replace the filter and install a new gasket.
I'm assuming the fluid in it now is the original type A and there will be fluid left in the system. Wondering how compatible the newer fluid will be with the type A still in the trans.
 
I'm assuming the fluid in it now is the original type A and there will be fluid left in the system. Wondering how compatible the newer fluid will be with the type A still in the trans.
Drain the convertor and you'll have no more than a quart left in the trans... If you are still worried, change the fluid again next year. I would be far more worried about the color of what is coming out. If it's still mostly red you should be good to go.
 
And why are the shifts former? Because it doesn’t lubricate well, it grabs because it’s not slippery. True story. I know many folks use type F with no problems, And that’s great. But I’m telling you the truth about what you are getting with the F.

I trust my mechanic with over 30 years wrenching, building engines, drag racing etc. with his recommendation to use Type F in 727 transmissions that will be used in high performance applications or in those that see more severe use due to more aggressive driving.
 
thanks for the incite guys.
the car has 86K original miles when it was stored in 1974. Pan gasket is seeping fluid so I will drop the pan, replace the filter and install a new gasket.
I'm assuming the fluid in it now is the original type A and there will be fluid left in the system. Wondering how compatible the newer fluid will be with the type A still in the trans.

To be more specific, as I said above that I run ATF+4, a filter change and refill is exactly what I did, refilling with +4. So I'm guessing my fluid is about a 50/50 mix with the original fluid. That was 4 years ago and everything runs fine. I asked a few local MoPar people before doing so and they assured me that the +4 was backwards compatible. Smooth shifts, no slipping. Of course your results may vary and I might be rebuilding tomorrow:rolleyes:
 
Valvoline Dexron III. Be sure to drain the torque convertor and flush the trans radiator cooler. You will have better performance w/ less fluid break down using a premium quality fluid. Cheap fluid is just what it is, a premium fluid will give good performance for many miles of driving.
 
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