ATF Type F, G, Dexron

[88v8]

So the original spec for my Borg Warner 66 called for Type G fluid.
I also see recommendations for Type F.

I've been using Dexron III for years, perhaps wrongly.

I can't find any comparison between Type G and Dexron III.

Anyone any ideas please?

[DiDueColpi]

All the old BW boxes, 35, 65, 66. Use type "G" Or the old Ford Type "F"
The newer designation is "TQF" or "AQF".
Dexron should never be used. The clutch linings and seals were never designed to handle Dexron fluids.
However, if you are running Dexron now, do not change it back to the original type fluid.
The seals and clutches will have absorbed the Dexron and the trans is now addicted to it.
Changing fluid types now will most likely cause a failure.
If the "66" was rebuilt in the past it's very possible that Dexron compatible seals and frictions were used which would explain your good fortune.

Live like you mean it
Fred

[88v8]

Thankyou.
The box has been fed Dexron for 15 years, and has been rebuilt, so as you say I'd better stick with what I have.

From what I've read, Dexron gives a softer shift, so maybe no bad thing.

[ag1234]

Way way back in AT class, a "trick" for GM automatics was to switch from GM fluid to type F for a firmer shift.
                                                                                   Onward,  Art.

[MGBV8]

Did not know that, Art.  Then again, I am a 4, 5, or 6 speed guy.  I have only drag raced with manual transmissions.

[ag1234]

I know, who cares/lol. Two items helped the GM T400 achieve such respect. 1. All upshifts RELEASE frictions to complete.
   2. Being a long main case, a center support bolt, near center of valve body, anchors the internals, (girdle).
                                                                                         2 cents,  Art.