Dexron Backwards Compatibility

Posted last week about a harsh 1-2 shift on my 93 Caprice. Turned out to be a misadjusted TV cable (Thanks Loafer). I’m getting a fluid/filter change done. The manual requires Dexron II. All the ATF fluid I’ve seen is either Dexron IV or Universal (Dexron/Mercon). I’m leery of anything universal and wondering if Dexron IV is backwards compatible with Dexron II, especially on an older car (i.e. effect on seals)? Would it hurt to add a bottle of Lubegard Red as part of the fluid/filter change?


Ed B.

I’ve used the newer Dexron/Mercron on older transmissions that called for Dexron II without a problem. However that doesn’t mean there won’t be a problem with your car. I did however use full synthetic, so that may have made a difference.

I run Mobil Dexron III/Mercon universal TF for over a year in my cars with no problem. Another vehicle has the SuperTech version, and again, no problems. Don’t know about Dexron VI, though.

I seem to remember transman mentioning a while ago he always puts a bottle of Lubegard Red in all the transmissions he rebuilds, so if my memory is right, then I’d say it’d be a decent idea.

Call a GM dealer and ask if they have fluid for a 93 Caprice. I am not suggesting that you buy it. Just ask what they have that “fits”.