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Dexron III or Dexron VI?

Brammer

New member
2002 GP GTP 99k I suspect it's on the original fluid, starting to smell a little off. Time for a fluid and filter change. Should I go with Dexron III or the newer stuff? Also, is the Dex/Merc stuff good for DexIII requirements?
 


pull the dip stick red it, use what ever it says to use.

new dex is thinner. not always the best for a older dex 3 tranny. as far as im concerned any ways, other say use and its fine. ill just use what it is supposed to use.
 
I AM ON MY 4th TRANSMISSION 1999 Grand Prix GT 170,000 miles. I just had the filter changed on this 4th one at 25,000. The remanufacture company used Dex 3 when this transmission was put in and recommends changes only be Dex 3. I regularly service my transmissions at 30,000 mile interval's. Who knows if the other transmissions went because Dex 6 was put in? I call up some trans oil companies and they recommend the Dex 6 equivalents of DEx 6. When I asked them why they said because that's what GM recommends and they cant recommend something else. 4 transmissions later do I have to spell out what I think of anything GM recommends.
 
I AM ON MY 4th TRANSMISSION 1999 Grand Prix GT 170,000 miles. I just had the filter changed on this 4th one at 25,000. The remanufacture company used Dex 3 when this transmission was put in and recommends changes only be Dex 3. I regularly service my transmissions at 30,000 mile interval's. Who knows if the other transmissions went because Dex 6 was put in? I call up some trans oil companies and they recommend the Dex 6 equivalents of DEx 6. When I asked them why they said because that's what GM recommends and they cant recommend something else. 4 transmissions later do I have to spell out what I think of anything GM recommends.

sounds like you need to buy a ford.
 
2002 GP GTP 99k I suspect it's on the original fluid, starting to smell a little off. Time for a fluid and filter change. Should I go with Dexron III or the newer stuff? Also, is the Dex/Merc stuff good for DexIII requirements?

probably fine with either. if you arent in a performance application i would say stick with III since its cheaper...

before i had mine built by TEP i ran III.

just dont flush the trans or you will have issues.
 
I AM ON MY 4th TRANSMISSION 1999 Grand Prix GT 170,000 miles. I just had the filter changed on this 4th one at 25,000. The remanufacture company used Dex 3 when this transmission was put in and recommends changes only be Dex 3. I regularly service my transmissions at 30,000 mile interval's. Who knows if the other transmissions went because Dex 6 was put in? I call up some trans oil companies and they recommend the Dex 6 equivalents of DEx 6. When I asked them why they said because that's what GM recommends and they cant recommend something else. 4 transmissions later do I have to spell out what I think of anything GM recommends.

Or stop throwing in JY transmissions because I'm sure you would of been on your 2nd one had you had the right place rebuild it for you


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When I did a pan drop / filter change, I added 7-8 quarts of dex 6. It meets and exceeds all OE requirements of Dex III, plus my local parts store didn't even carry Dex III.

Im 35,000 miles on Dex 6 without an issue.
 
Dave @ TEP recommends DexIII.

Thicker fluid...OE specs. I've ran DexIII always. Never had an issue.
 
I've ran about 15,000kms on deck 6 with an intence shift kit and no issues. I also had a hard time finding dex 3.
 
I've run and dumped both into these 4t65's.. the problem isn't the fluid..it's the transmissions.

Go cheap and you'll feel it less when it grenades.

Japanese huh?
 


Super tech dex iii/mercon is what I run in everything but the G8 (super tech dex vi). Been using it for a while, cheap and effective, and easily found at walmart.
 
Dexron VI is full synthetic and is backwards compatible with III. GM switched from III to VI around the 2004-5 timeframe. I have been using VI with no issues.

I had a Jasper reman 4L80E installed in my '01 Suburban and they require a 5K fluid change after install. I called their tech hotline to ask whether III or VI, and the guy wouldn't say, he said either was fine. So right or wrong I made the decision to use VI in all my GM vehicles.

FWIW, if you're on your 4th trans in such few miles you have bigger problems than what fluid to use.
 
I did complete swap to Dex6 with pan drop, no issues... Can't see how there would be... Slippery shyt that tranny stuff! Lolz...
 
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