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
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