UOA, DexronVI, 26k miles, GM 6L80

[jetman]

I got the lab results back from JG Lubricant Services whom I use for all my used ATF analysis. I talked on the ph at length with Tom Johnson, their co-owner and President, about these results and about atf in general. He assured me that everything looked good, and to not change it. I'll submit another sample in a yr. He said a yr from now my results would more than likely my results will be good again. But stuff happens, right? The cooler in the radiator could start leaking, etc. Unless you send in a sample you just never know.

JG Lubricant Services contracts OAI/Polaris Labs to do the lab work, and they don't show the universal avg info on their reports. So I found somebody else recent results from Blackstone about Dexron VI out of their 6L80 and copied the universal avg #s from their report and included them below for our comparison.

My 07 Yukon Denali has 157,200 miles, and 4818 hrs, since new. 17 mths ago I purchased it from a used car lot without any mx records. 16 mths ago I removed the trans, etc so as to replace the engine rear main seal. While I had it out, I decided for preventative mx to replace the torque converter with a newly rebuilt HD one. I also removed and cleaned its pan, replaced the filter, and reinstalled w/10 qts of AC Delco Dexron VI.

The first #s below are Blackstone Labs "universal averages" for 44k mile Dexron VI fluid out of a 6L80 trans.
The second #s are for my 6L80 trans and ACDelco Dexron VI after 26k miles, and 16 mths in use.
As you can see, all of my #s are lower than the averages, as they should be.
Aluminum........ 22.......12
Iron..................98.......74
Copper..............49.......42
Manganese.......22........9
Boron................67.......66
Silicon...............22.......7
Sodium.............11........7
Calcium............84.......66
Phosphorus....209......170
Zinc..................15........6
Viscosity @ 100*C - acceptable range is 5.1 to 7.9; mine is 5.7
my acid# is .61, and my oxidation# is 17, both ok.

I found out about Tom around 2010 on a motorhome forum he contributes to.

Here's a link for JG Lubricant Services: https://jglubricantservices.com/productsservices.html

And here's a technical paper(4 page pdf) Tom authored. The last paragraph gives his credentials: https://jglubricantservices.com/docs/Technical Information Sheet.pdf

 

[dnewton3]

The UOA looks fine.
I did extensive research on the DexVI vs TES-295 applications more than a decade ago. I came to the conclusion that DexVI is a perfectly good fluid that holds it's vis very well (it's primary goal). I've got a LOT of UOAs from many different applications for the typical Dex/Merc, Dex VI, and TES-295 applications. Overall, those ATFs do well in most applications they are intended for. DexVI is a perfectly decent fluid that does very well in the GM 4L60/80 and 6L80/90 applications and their derivatives.


A little historical perspective:
Tom Johnson lives in the western metro-Indy area; he retired as an engineer from Allison Transmission where he worked at the Indy location for quite a long time. He told me he was instrumental in putting the TES-295 spec in place for Allison. I'd spoken with him many, many years ago about the DexVI seal compatibility issue in some Allison applications, etc. Our past member Whitewolf worked for GM as one of their ATF lube engineers; I also spoke directly with him way back in the day as well. There was some disagreement between them about that topic, although it was not universal condemnation by any means; just an agreement to disagree.