Thread: Dex 3 or 6

I am going to be installing my Dynotech Transmission in a week.It was run with Dex 6 for 3500miles.Seeing how i do not know if i will like how firm or soft the shifts are should i just use the Dex 6.Not sure if i will have to drop the pan.I heard that if the product has Dex 6 from day one Dex 3 is not allowed.But if it had Dex 3 you can use Dex 6.

In my car too. It's going to be increasingly hard to find Dexron III since GM stopped making it and recommends Dexron VI be used in all Dexron III applications.

Plus its $5 a quart.

I just buy it by the gallon. Usually from ZZP since I get a discount and am buying something else anyway. Comes out to about $5 a qt.

At my work its genuine GM Dex 6 i can get for $5 a quart.So that ='s $60 for 12qts since the transmission and converter is totally dry.Vs. i can get Dex 3 for free.

I noticed a great improvement going from Dexron III to Dexron VI. Worth the $60, to me. This is your transmission we're talking about, and they are expensive.

You saying it isn't worth the $60 to make it all it can be?

Originally Posted by Sabrewings

You saying it isn't worth the $60 to make it all it can be?

Wouldnt that be like make it aim high for you?

1.5 years ago, I changed the fluid and filter in my GTP and used GM Dexron VI fluid. I bought it from paceperformace.com and it came out to be less than $5 a quart when buying it by the gallon. 6 months ago I did it again using Valvoline Dexron VI that I bought from NAPA at less than $4 a quart. Stuff from Wal-mart should be even cheaper than that, and work just as well.

I would definitely run Dexron VI in any GM tranny I can. Not only because it will be hard to find Dexron III, but because Dex VI is a much better fluid. Greatly improved and runs much better in my tranny.

Originally Posted by Reptile

Whichever brand you chose to use, Dex 6 has to meet the same formulation standards whether it's GM or Valvoline.

I vote Dex 6 because it's all around a better fluid.

It has to meet performance standards, not formulation standards. Big difference, as they're not necessarily all the same.

Originally Posted by Scimmia

It has to meet performance standards, not formulation standards. Big difference, as they're not necessarily all the same.

Actually, I believe it is both. There are minimum requirements of certain things that need to be in the Dex VI fluid. Not 100% sure, but I believe trans fluid has to meet both formulation and performance standards.

I will go with 6 then.

Hummm, when I installed my Race Tranny I used Dex 3 for mine. I didn't know if I should go w/ 6 or not, I didn't want to screw up anything.

Can 3 be mixed with 6? The reason I ask, I plan to drop my pan soon to check things out, dropping the pan only removes a little bit of the fluid. Wonder if it would hurt to stick in 6 to refill it or should I go back to 3?

III and VI will mix just fine. Dropping the pan gets over half the fluid. I personally don't think there's anything wrong with III, though, so if you're more comfortable with that, go for it.

Originally Posted by Iron Indian

Hummm, when I installed my Race Tranny I used Dex 3 for mine. I didn't know if I should go w/ 6 or not, I didn't want to screw up anything.

Can 3 be mixed with 6? The reason I ask, I plan to drop my pan soon to check things out, dropping the pan only removes a little bit of the fluid. Wonder if it would hurt to stick in 6 to refill it or should I go back to 3?

Dexron VI is a directly replacement for Dexron III and is 100% compatible. No issues with dropping the pan and replacing the missing fluid with Dexron VI. I did it on my GTP and my wife's malibu.

Sorry, it does NOT have to be the same formula. They have specific performance and viscosity standards, and I believe GM does say they have to use certain additives and not others, but that doesn't make it the same formula. Motor oil have standards like this set by the SAE, does that mean that all 10W-30s are the same formula?

Dexron 6 is a standard, not a formulation.