Name : Cliff Joined : 2020-09-01Post Count : 133 Merit : 1
Subject: ATF fluid Sat Nov 21, 2020 8:15 pm
Im in the process of changing all the fluids on my 96 project car and next is the transmission fluid. In Wal mart the other day I saw bottles of atf fluid labeled to be for older cars with over 75000 miles that used to require dex III. Then there is dexron VI and the original dexron III. I also read an internet article on how to prolong the life of 4t60e transmission and one of the tips was to stick with dex III. What's the consensus here on the best fluid to use. Thanks.
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8687 Merit : 181
Subject: Re: ATF fluid Sat Nov 21, 2020 9:20 pm
Cliff96 wrote:
Im in the process of changing all the fluids on my 96 project car and next is the transmission fluid. In Wal mart the other day I saw bottles of atf fluid labeled to be for older cars with over 75000 miles that used to require dex III. Then there is dexron VI and the original dexron III. I also read an internet article on how to prolong the life of 4t60e transmission and one of the tips was to stick with dex III. What's the consensus here on the best fluid to use. Thanks.
There isn't a consensus, and consensus does not matter on this topic. Some people use Dex III and change it (drop pan and refill) every 20-30K miles, some people have never touched their transmission fluid, some use Dex VI, and some use Valvoline Dex VI/Merc, and some use Valvoline Max Life ATF (Dex VI compatible). Those using Dex VI and compatibles are going 50-60 K miles between fluid changes with no apparent issues. There are several workable approaches, and as long as you (1) are consistent (2) if you switch to Dex VI - NEVER - switch back, you'll be fine.
Do some searches for 'transmission fluid' on the site for context and insights.
Albertj
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Cliff96 Enthusiast
Name : Cliff Joined : 2020-09-01Post Count : 133 Merit : 1
Subject: Re: ATF fluid Sun Nov 22, 2020 8:18 am
Thanks for the reply. When you said never switch back to dexIII it created a problem for me. The p.o. had a new/used transmission put in a few months ago and I'm not sure what type fluid it has in it now? Not sure what to use now.
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8687 Merit : 181
Subject: Re: ATF fluid Sun Nov 22, 2020 7:28 pm
Cliff96 wrote:
Thanks for the reply. When you said never switch back to dexIII it created a problem for me. The p.o. had a new/used transmission put in a few months ago and I'm not sure what type fluid it has in it now? Not sure what to use now.
Just use Dex VI or its compatibles (Valvoline MaxLife).
The real headache with Dex III is that GM is no longer policing the Dex III standard. As a result, a number of the Dex III fluids will work - but won't work all that long, depending on your driving you'll likely scorch the fluid in 20-30 thou miles.
Some trivia for you - https://en.wikipedia.org/wiki/DEXRON
