Currently I have Dexron III type ATF in my 4L60E, I just picked up 6 quarts of Dexron VI from the local dealership which had it in stock, since I had to order new tensioner for the main and the a/c belt.

I was thinking about when I do the ATF fluid change, the Dexron III type will still be in the valvebody and in the converter, in which the new fluid I'm replacing would be Dexron VI, would it be ok if some Dexron III mixed with Dexron VI inside the transmission until the next change?

 

It should be just fine.

But if you do want to change ALL you fluid, see this: https://ls1tech.com/forums/showpost....1&postcount=10

 

Thanks! I just brought a case of Dexron VI for this prodecure.

 

I just did the filter, added in 5 quarts.
Measured 8 quarts line in the bucket, added 8 quarts while the engine is running and the old ATF pouring out of the cooler line plus some fresh fluid can be seen coming about 3/4ths of the way through to the 8 quarts line.

After checking the fluid (trans cold) the fluid line is like at the looped end of the ATF dipstick. Looks like I'm about 2-4 quarts low on fluid.

Back out to get more Dexron VI.

 

Sorry about that, procedure should have said to have an extra 3 qts just in case.

I always have extra quarts stocked in my house.

Edit: procedure updated.

 

That's ok. I had to take my '74 Nova on a 15 min trip to the chevy dealer and pick up 4 quarts of dexron VI.
I used 3 quarts and now it's at the top of the HOT line when the engine is hot.

 

What do you think of this new fluid?

I can't really find any info on it yet.

 

So far so good. I can notice the cooler is like just a lil bit cooler than it used to be.

I don't have AutoTap so I can't tell for sure.

Main point with this fluid is that it's supposed to run 15*C cooler and supposed to be better than Dexron III. All of GM new cars and truck uses it unless it's a heavy duty fluid for a truck.

 

Any difference in the shifting?

TCC lockup feel any different?

 

Bump.

 

Should you be mixing the 2 like that? 4ish qrts of DexronVI, and the other 10ish qrts dexron III? If your gonna change over Use a T-Tech to flush ALL of one out to replace with the other.