Mix Sythetic Atf With Dexron Iii?

[lexes]

I'd like to put synthetic ATF in my car. Is it ok just to drain and fill once or twice with synthetic and the end result will be a mix of synthetic and dexron III, or I have to flush it and fill it completely with synthetic. TIA for any help.

[godfather18]

I'd like to put synthetic ATF in my car. Is it ok just to drain and fill once or twice with synthetic and the end result will be a mix of synthetic and dexron III, or I have to flush it and fill it completely with synthetic. TIA for any help.

You will damage your transmission if u mix it with anything else other than Dexron III. Drain and fill with fresh dexron III or just flush with dexron, but DONT put that other stuff in your trans, also put a trans filter on to prolong your transmissions life.

[lexes]

Thanks for the reply. so people who convert to synthetic they have to do a complete flush?

[mburnickas]

I'd like to put synthetic ATF in my car. Is it ok just to drain and fill once or twice with synthetic and the end result will be a mix of synthetic and dexron III, or I have to flush it and fill it completely with synthetic. TIA for any help.

You will damage your transmission if u mix it with anything else other than Dexron III. Drain and fill with fresh dexron III or just flush with dexron, but DONT put that other stuff in your trans, also put a trans filter on to prolong your transmissions life.

I do not understand your post..you can have a synthetic DEX3 and a dino DEX3...

I have mixed both when going to synthetic since 1996...never had any issue. Fluid basetock you will not have issue, not fluid spec's it passes and types is a different issue.

[m2pc]

I agree with mburnickas,

I've been doing the last 4 drain and fills Dex III Synthetic (Redline D4) and 60,000 miles later, tranny still runs fine.

[lexes]

my question was if I can mix synthetic ATF (specifically Mobil 1 synthetic ATF) with dino Dex III currently in my car? thnx

[Toysrme]

You can mix anything, with anything, provided it all meets the required specification.

When that transmission fluid get's pumped at 250+psi in the valve body, ya baby. It's mixing time! It's no different than oil. When it get's pumped through the oil pump at 70+psi when you're on the gas, it's gunna mix.

[lexes]

thanx for the response. This is what is said on mobile's website

====================================

Specifications and Approvals

Mobil 1 Synthetic ATF has the following builder approvals:

Allison C-4

Ford Mercon

General Motors Dexron III

====================================

So that means Mobil 1 synthetic ATF is 100% Dexron III compatible, doesn't it?

also another question I have is, is the ATF still good if it's too old. I have some ATF that's probably more than 6 years old.

TIA

[Toysrme]

Im not an expert, but my feeling / idea has always been that as long as it doens't like "come apart", then yes.

It's the heat / time of actual useage on things like oil & atf that ruin them. AFAIK oil doens't just "go bad" sitting around.

[Lexusfreak]

I do not understand your post..you can have a synthetic DEX3 and a dino DEX3...

I have mixed both when going to synthetic since 1996...never had any issue. Fluid basetock you will not have issue, not fluid spec's it passes and types is a different issue.

I also agree with mburn. B) I also prefer Castrol Syntec Dexron III synthetic over Mobil 1 synthetic ATF personally.