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727 Trans fluid question

Loulang

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I am changing the filter in my 727 trans but I’m not sure what kind of trans fluid is in it and a lot of posts say to use type F trans fluid my question is what if that’s not the fluid that’s in it already will it hurt my transmission to put type F in?
 
ATF+4 should work just fine. It's Mopars synthetic fluid.
 
I always stick with regular atf. +4 is the synthetic version. You're on your own with the type F conversion. Some people use it regardless and haven't shown any I'll effects. It lacks some friction modifiers.
My own testing involves a trans I built 20 years ago and has proven 9 track championships and still in the car today.

Edit I ran type F the first year and **** went down so I stopped that.

Don't search this topic you're head will explode
 
I always stick with regular atf. +4 is the synthetic version. You're on your own with the type F conversion. Some people use it regardless and haven't shown any I'll effects. It lacks some friction modifiers.
My own testing involves a trans I built 20 years ago and has proven 9 track championships and still in the car today.

Edit I ran type F the first year and **** went down so I stopped that.

Don't search this topic you're head will explode
I think I’m gonna go with the atf+4 I hate not knowing what’s in it. I got no info other than motor and trans was rebuilt and you can tell that’s why I bought my 66
 
Stick with what Mopar recommends. They would have tried Type F and......
 
Stick with what Mopar recommends. They would have tried Type F and......
They did and promoted it at the performance clinics. A short term performance enhancer .
Transmissions were cheap back then.
 
What about Dextron III? I just got my trans kit and want to change the filter, gasket and helicoil a couple of bolts. Have a 727 trans and sometimes it shifts hard.

RemCharger is correct about the my head exploding. Seem like no 2 people using the same fluids
 
I read decades ago that dexron had modifiers in it to make the shifts softer for granny, that type F made the trans shift harder, and cleaner. Started using F in everything, GM included, glides and turbo400s with brakes, and have found no reason to change.
I WILL use the recommended stuff in new computer controlled cars and trucks.
 
What about Dextron III? I just got my trans kit and want to change the filter, gasket and helicoil a couple of bolts. Have a 727 trans and sometimes it shifts hard.

RemCharger is correct about the my head exploding. Seem like no 2 people using the same fluids
Dexron II /III is the factory specified fluid.
 
It's tough to make this call due a lot of
cheap China crap parts being used in
rebuild kits. Also, clutches and bands
may not be manufactured with the
same materials that Mopar used on
their parts years ago. So what worked
then may not be the best choice now,
if your trans has been rebuilt.
I run Royal Purple Max, but that's with
a fresh rebuild. Shifts fine, no leaks.
 
When I built my 727 Pat Blais (aka Torqueflite Patty) advised me to use Type F. Since it was a fresh build I didn’t have to worry about incompatibility between fluid types. I’ve had no issues whatsoever…
 
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