Trans fluid recommendation

[C- Bodies Rock]

Time to top off my '69 Fury 318/TF trans fluid..(leaks a little, maybe a pint in 2k miles, out the tail shaft..no plans to replace the seal or drop the pan any time soon)I have no idea what fluid is in the transmission..(shifts fine).. which fluid should I use that won't cause any compatibility issues with whatever fluid is in it ?? ..thanks all..

 

[tbm3fan]

I've put Dex/Merc in mine. I know some use Type F and I have a lot of Type F laying around with my Fords but I still used...

 

[70bigblockdodge]

Type F, I am not as trusting of backwards compatibility. New transmissions do not use bands, your 727/ 904 does. Not that Dex/Mercron is for new transmissions so it is probably fine.

 

[1978 NYB]

I would recommend type F for a 727 too.

 

[73Coupe]

Keith, the 727 specialist recommends ATF+4

 

[Carmine]

Type F provides a firmer shift and less heat because the friction properties are different than Dex II (the oem), which allows more clutch slippage. For this reason, I've always used Type F(ord) for complete refills (in old tymey transmissions only!) . If I were just topping off as the OP is doing, I'd use the Dex/Mec stuff that's commonly available (and cheap).

If I found a '69 Fury in the middle of the desert with a trunk full of ATF+4, that ran well but was low on trans fluid, I'd add it because it's better than dying. But the whole time I'd be thinking "This crap is $8 a quart, I wish I could save it for my minivan that really needs it."

 

[Wile E Coyote]

My engine builder - Hensley Performance, Knoxville, TN - says Type F. That's all I use in my fleet; zero problems. He says there's nothing wrong with ATF+4 but he said the same as Carmine about the firmer shift/less heat with Type F.

 

[Big_John]

When Bill Hancock (Arrow Racing Engines) worked for Chrysler back in the seventies, he told me that type F was the better choice for performance cars. The difference was that Type F had more "friction modifiers" and there would be slightly less slippage. All else was the same as Dexron.

He used "Momma's Imperial" as the example in a thick southern accent.... I still remember it.

 

[polara71]

Interesting information

 

[68plymouth383]

Type F has done me well in my 3 727 transmissions

 

[Dana]

Dex/merc or atf +4. I can't agree with the less heat and type f theory. You can always tell a type f 727, the steels will have premature blueing and hot spots. Too much friction modifier. Sure they shift nice and firm but it comes at a cost.

 

[Carmine]

Dex/merc or atf +4. I can't agree with the less heat and type f theory. You can always tell a type f 727, the steels will have premature blueing and hot spots. Too much friction modifier. Sure they shift nice and firm but it comes at a cost.

Reducing the time a clutch slips = reduced heat, not more heat. The effect of fluids on bands is minimal (other than not having enough). But your experience may vary. I'm certainly voiding the manufactuer's warranty!

 

[70bigblockdodge]

The clutches in a 727 are way over built. You can put really big power through stock clutches. If your blueing steels from slipping something is wrong.

 

[system11]

Seems to be the most recent thread for this question - I've spent hours with google just coming up with lots of conflicting opinions and advice. 727 Torqueflite, is a semi synthetic dexron III the way to go, or a fully synthetic III or even VI?

 

[Yeahrightgreer]

Seems to be the most recent thread for this question - I've spent hours with google just coming up with lots of conflicting opinions and advice. 727 Torqueflite, is a semi synthetic dexron III the way to go, or a fully synthetic III or even VI?

Realistically - any modern Dex III and up atf is going to be pretty much compatible with your 727 and won’t ruin its lifespan. Especially if it’s a high mileage transmission.
People can say what they want about what the service manual states - and what the pros use, but unless you’re racing and putting a constant or extreme amount of stress on your cars driveline, the effect will be negligible to its lifespan, response, and drive quality at the most.