Thanks for this link. Was way more interesting than I initially thought it'd be. Starts out kinda dry, but you can see that this guy has a passion for what he's doing. I got a kick out of him chuckling at some of the stuff he was talking about.
My biggest "personal" takeaway, if I understood what he was saying about backwards compatibility: Dexron VI is NOT backwards compatible to A. And that MAYBE Dexron III(H) is.
OK.
If that's the case - since GM no longer licenses Dexron III, all we can do is use ATF that
claims compatibility, like the ubiquitous "Dex/Merc" fluids. And/or specifically look for ATF meeting the "Allison TES-389" specification, which Allison started specifying when GM no longer licensed Dexron III. (Assuming THAT'S still an active specification!)
As far as Type F: I think, ignoring the "base stock" component, the
main difference between Type F and Dexron (and Mercon, and Dex/Merc) was the difference in the friction modifier package - F has fewer friction modifiers / is "grabbier". In my Dynaflow I don't think I'd see a lot of difference between A, F, or Dex/Merc. In a "shifting" transmission, you might. I've even seen posts saying some shops (years ago, nothing modern) used Type F to "firm up" a slipping or "soft" GM transmission. Sounds like voodoo but - if it's stupid but it works...
Aside: I actually have more modern (90s) vehicles that still use Type F as specced from the factory -
in their Power Steering pumps. That's apparently the only reason that "licensed" Type F still exists - Ford maintained that specification just for power steering for pre-95 vehicles. And the thing with Mercon (and later, Mercon V) being backwards-compatible with Type F? Ford doesn't say it is
for Power Steering. Why? Don't know. (And I personally doubt Mercon V would be a good choice for an original Ford "Type A" or "Type F" transmission ANYWAY - at least, one that hasn't been rebuilt with modern clutch packs, due to friction modifiers.) But I suspect that's the only reason that branded "Type F" ATF is still around. Heck, you can still get
Motorcraft Type F.
Speaking of "base stock", I think another variable I'd consider is "maintenance intervals". I tend to stick with the severe duty intervals (for the reasons stated in that video, again, impressed with the detail there). And the modern Dexron III has a
much longer maintenance interval than F. Better base stock, better additive packages.
So that'd probably send ME down the Dexron III(H)/Allison TES-389 path. I'd be looking for something that's known-compatible...that has a more modern base stock...that's available...probably be a Dex/Merc I'm guessing.
What would that do for you? No idea!
