Atf+4 vs Dexron vi

[Johnny2Bad]

Originally Posted By: pjc360
Isn't it bad to run the transmission in neutral with fluid pumping out of the cooler line? I thought I've heard that can burn them up.


If you follow the procedure, no. Note that 3+4-speed Chryco auto transmissions (not sure about the newer 6+ speeds), the pump doesn't operate in Park, that's why you do the procedure in Neutral.

 

[pjc360]

Yes I am aware of that, that's why you check the fluid level in nuetral. And I always let the truck warm up idling in nuetral so the transmission fluid circulates and gets warmed up.

 

[Whitewolf]

Originally Posted By: pjc360
4.2 cst? That's pretty thin. How many miles does it take to make dex III shear that much? I only have about 5000 miles on th dex III that's in my transmission.


It goes really quickly down to the mid 5s in the first few thousand miles and then the degradation slows down to eventually reach the sort of figure that I mentioned by about 60k or so.

 

[pjc360]

Wow so dexron III is not a shear stable fluid then, I wonder why it shears so quickly. Is it the additives they used to develop dex III? Or is it the fact that it's a Dino oil?
The only thing I like about the dex III in my transmission is I like the way it shifts with it, not too harsh but not super soft ether.
Bit I've heard some people say that the chrysler +4 fluid doesn't cause soft shifts, I've heard people say it does and I've heard people say it doesn't.
The dex vi should feel about the same shift wise as the dex III in my transmission right?

 

[MolaKule]

Originally Posted By: pjc360
Wow so dexron III is not a shear stable fluid then, I wonder why it shears so quickly. Is it the additives they used to develop dex III? Or is it the fact that it's a Dino oil?


DexronIII was primarily a mineral oil with a Viscosity modifier that was not as shear stable as today's VII's.

Originally Posted By: pjc360
The dex vi should feel about the same shift wise as the dex III in my transmission right?


I would say it would be close.

 

[jrmason]

You have to remember Dex III was introduced around 93-94. Very outdated technology compared to what's available today.