Tranny fluid

I know the recommended is DEXIII. I bought some DEX/MERC and ran in my tranny before I fixed the shifting issue (bad tranny solenoids).

I didn't encounter any issues with the transmissing shifting.

After I fixed the shifting issue, I put most of the tranny fluid back in (as it was still good) and added some more DEX/MERC to the tranny. I encountered some random slipping.

Is DEX/MERC simply an ATF +3 or ATF+4 that is just labeled differently? If so, I'll need to source some DEX III.

I believe atf+3 is semi synthetic and atf+4 is full synthetic but also have different friction modifiers than dexIII. Dex/merc is a universal fluid that will work for dexIII and Mercon V. I try to stay away from the universal stuff.

Is there any place you can still get DexIII or an equivalent?

Believe it or not, look at any of the major parts stores for their cheap house brand. I have found it at both advance and autozone. As long as it says Dex II/Dex III on it, it should be fine. I have no problem with the Dex/Mercon as long as it has DexII on the bottle somewhere. That's what I use and no problems.

bigalpha said:

Is there any place you can still get DexIII or an equivalent?

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I have recently been sourcing DexIII from NAPA. It is NAPA brand and clearly labeled as DexIII. Three different NAPA shops all told me that it was "made by Valvoline for NAPA." Could be true... seems to be fine fluid.

I get Formula Shell Dexron III, at the local BJ's club for $25 a case.
It's authentic Dexron III, must be old stock. I've not seen this stuff anywhere else.