trans rebuild: dex 6 a good choice?

[White93z34]

I am about to have a 4t60-e rebuilt next week and i am considering using dex 6 instead of dex3/merc. what benefits would i get from this if any?

[19Cutlass94]

probably just a longer change interval. I would just stick with your fav sythnetic tranny fluid.

[GutlessSupreme]

I dunno about GM fluids, but I know of certain cases where the newest fluids will be detrimental to older equipment.

 

example: In most cases, you're not supposed to use DOT4+ fluids when the system calls for DOT3

 

There could be vast differences between Dexron 6 vs. 3. Newer transmissions may call for different lubrication/friction, viscosity and heat properties than ours, which is usually why a new standard (Dex 6, ATF4) is made. Just because it's a higher number doesn't mean it's better, it could be the same difference between using synthetic 0W20 and conventional 20W50.

[Andrew]

I had a talk with a GM mechanic awhile back when he was trying to convince me to have a trans flush done at the dealer. I laughed at him. Anyway, going from Dex3 to 6 is fine, as long as all the old Dex3 is flushed out. Seeing as how its going to be rebuilt and empty, going to 6 will be easy and a good idea. Some linked to a site a while back regarding 6, and its superior to 3 in several ways.

 

So in short, I'd do it.

[pwmin]

i would get some amsoil synthetic ATF and call it good. thats what my cobalt manual trans uses

[White93z34]

what i am asking is would it be GOOD to use it in a REBUILT transmission, IE system flushed of all OLD dex3.

[digitaloutsider]

I dunno about GM fluids, but I know of certain cases where the newest fluids will be detrimental to older equipment.

 

example: In most cases, you're not supposed to use DOT4+ fluids when the system calls for DOT3

 

DOT4 is completely compatible with DOT3. And Dextron VI is designed to be 100% backwards compatible.

[mfewtrail]

Dexron IV is supposed to be backwards compatible with all GM autos, so run it if you want to.

 

EDIT: Shaun beat me to it.

[pwmin]

from all i read, DOT-4 IS NOT compatible w/ DOT-3.

 

 

 

you two are talking about different stuff...IV vs. VI.

 

 

i would NOT use it. i would use syn ATF and MAYBE a little Type F for firmer shifts

[greencutlassdrvr]

theres dex 6 out already damn... were behind we only have dex 3 and dex 4 lol

[BIGBULS]

As was mentioned, Dex VI (no such thing as Dex IV BTW), is 100% backwards compatible.

 

Also, while DOT 4 brake fluid is not NECESSARILY compatible with DOT 3, many high temp/high performance brake fluids (such as Motul RBF 600, ATE Super Blue etc) are both DOT4 AND DOT 3 compatible...........so to a POINT, they CAN mix (kinda).

 

 

 

 

 

Back on the trans fluid.

 

*MY* choice would bre a rebuild with Mobil 1 Dex III. The Amsoil stuff is marketed as a "universal" trans fluid, which is BS........no such thing (although, they ARE usually fairly close....which is why Amsoil think they can get away with it)..........I figure HARD use is where a universal ATF is going to become the weak link.

 

Anyway, Mobil 1 and (I think) Redline both make a fully synthetic ATF Dex III, and THEY would be the ones I'd go after.

 

But nothing WRONG with Dex VI.........it DOES have a little higher temp threshold I gather (than Dex III), but since your car doesn't NEED Dex VI (just a "better" fluid), *I* would be using a synthetic Dex III.

 

 

 

Here:

 

http://www.mobil1.com/USA-English/MotorOil/Other_Products/Mobil_1_Synthetic_ATF.aspx

 

http://www.redlineoil.com/pdf/3.pdf

[Dark Ride]

I remember reading somewhere that Dex 3 and 6 can be mixed together with no problems. I ran out of dex 3 and added dex 6 but I only drove the car around the block since then, so I'll have to see how it holds up, I'm sure it'll be fine though.

[boulevard]

i would get some amsoil synthetic ATF and call it good. thats what my cobalt manual trans uses

 

FTMFW! Yes!

[mfewtrail]

(no such thing as Dex IV BTW)

 

I didn't realize I had transposed those letters.