Transmission Fluid--Which to use?!?!?!

[Truston Gunter]

It was time to service the transmission with new fluid and filter. I went to rockauto and ordered 7 quarts of ACDELCO Dexron-VI transmission fluid, part # 10-9394 and a gm filter 24258269. Did the service, kinda easy except for the checking of the fluid. Not hard just inconvenient how its suppose to be done. Everything is great right, well I forgot to account for the transfer case as well so I didn't have enough fluid to service that. I went into my garage to see if I possibly had some left over tranny fluid from previous vehicles (I've always owned GM products) and sure enough I did! HERE IS MY QUESTION........ what I have on hand is ACDELCO Dextron VI part # 10-9243. Different part number from what I ordered and already put in the vehicle? Is this a major screw up on my part? What is the difference between these two??? Can I use them interchangeably??? I know one says full synthetic but I was under the impression all dextron VI was full synthetic??? See pic for reference

[Another JR]

I wouldn’t mix fluids in the same system even if they meet the same spec. The transfer case does not share fluid with the transmission so no problem using your different part number fluid for that.  The other concern would be age of the fluid if it has been sitting several years. Do some research yourself if your fluid is older, but I’ve read recommendations not to use engine oil that has been on the shelf more than five years. One of our resident oil experts here may have advice on that. 

[carkhz316]

It'll be fine. Its just a revised part number. Same fluid otherwise. And the age isn't going to be of any concern.

[Truston Gunter]

Mixing the fluids is my main concern. Of course it was unintentional. Someone can correct me if I'm wrong but when you drop the transmission pan and replace the fluid and filter, your only seeing 1/3 of the total capacity ( I many be wrong on the amount, my point is its not all of the fluid). So I wanted to stick with the OEM which is why I chose ACDELCO "brand".  That's why I made this post to figure out if these 2 fluids are indeed the same and just different and/or "revised" part numbers. The fluid is about 3 years old but my assumption is that trans fluid has a relative long self life. Thanks for the input!  

[Another JR]

I would not be concerned at all using 3 year old fluid from sealed containers. 

Edited January 10, 2024 by Another JR

[Cold North Country]

-I have been wondering the same thing for both the Tranny and the xfer case.  What actually is put in at the factory?

-Summit Racing stocks 2 different ACDelco Dex VI, one says Mineral in the specs but nothing on the container, and the other says Synthetic on the container.

 

Mineral:

ACDelco 10-9395 ACDelco DEXRON-VI Automatic Transmission Fluid | Summit Racing

 

Synthetic:

ACDelco 10-9244 ACDelco DEXRON-VI Automatic Transmission Fluid | Summit Racing

 

[Grumpy Bear]

On 1/10/2024 at 8:58 AM, Truston Gunter said:

I know one says full synthetic but I was under the impression all dextron VI was full synthetic???

 

Nope. Dexron VI is a viscosity and additive spec, not a base oil spec. ACDelco Full Syn is a Group III and will take more heat than the Group I/II mineral variant. They can be mixed without operational issues. Add package is the same and blender blend various fluids all the time. Got an old SEALED bottle? Shake it well and use it. 

 

 

Edited February 3, 2024 by Grumpy Bear

[Another JR]

5 hours ago, Grumpy Bear said:

 

Nope. Dexron IV is a viscosity and additive spec, not a base oil spec. ACDelco Full Syn is a Group III and will take more heat than the Group I/II mineral variant. They can be mixed without operational issues. Add package is the same and blender blend various fluids all the time. Got an old SEALED bottle? Shake it well and use it. 

For you Mandalorian fans:

 

 

GB - if you are not familiar with that character, he regularly says, “I have spoken,” after telling someone his decision or how things are, to declare a discussion is over. After reading your post it immediately popped into my head that you should have closed your post with “I have spoken.”  

Edited January 11, 2024 by Another JR
Explanation for GB in case he hasn’t seen the show

[Cold North Country]

Thanks for the infos.  Sounds like synthetic is the way to go with GM wanting the Tranny to run so hot from the factory thermostat.  Still wonder if they factory fill with synthetic or mineral?

[Truston Gunter]

Sounds good thanks for the info. Kinda wish I had chosen the "full syn" but at this point it is what it is!!! Hopefully this tranny will last well past 100k, time will tell.........

[Grumpy Bear]

There is synthetic then there is synthetic. 

 

D6_ATF_PROD_INFO.pdf (redlineoil.com)

[bruceb58]

Is this a 10 speed or a 6 speed transmission?

 

If you have the 10 speed, you put in the wrong fluid. You need the ULV fluid which is "ultra low viscosity".

Edited January 19, 2024 by bruceb58

[Cold North Country]

OP signature say 2020 GMC HD so assume 6 speed.  I also have 2020 with 6 speed.  Yes GM state all different fluid for 6, 8, and 10 speed, all use different fluid.  Thanks

[bruceb58]

6 hours ago, Cold North Country said:

OP signature say 2020 GMC HD so assume 6 speed.  I also have 2020 with 6 speed.  Yes GM state all different fluid for 6, 8, and 10 speed, all use different fluid.  Thanks

Yeah...was trying to figure that out. I know the 10 speed was introduced in 2020 but likely only with the Duramax

[C/K Man]

ACDelco fluids often change part numbers and may have alternate part numbers for the same fluids.  For example, you may see 3 different part numbers for same spec. 5W-30 Dexos 1 full synthetic motor oil.  The only difference may be the supplier.  One may be Phillips 66, one may be Mobil 1, one may be Chevron.  Just read the label carefully, if it's the same description and the same spec. no harm in mixing.