I have a new converter and rebuilt / race prepped 727, and i want to put good fluid in it for the season. I have run ATF+4 in the past, but not sure what to do now.
Is that the fluid the person that did the trans is recommending ? =4 is the last fluid I would run in a trans that doesn't have a lockup convertor that needs to slip when applying ... then again I didn't run it in my 2000 Cummins Ram which is what the factory wanted , but my trans builder did not.
I'm with John on this one.
Newer fluids have more friction modifiers to make the fluid more "slippery". They do this to prevent harsh engagement, especially for the lockup convertor.
In an older transmission or anything race I never run anything but old school style fluids Dexron or type F that don't have as much of the friction modifiers.
Unless the builder or parts inside require a specific fluid then I go by those specs.
