Follow up to my 6L80E Fluid and Filter Replacement

[Sierra048]

Thought I would resurrect this thread for a follow up after more than a month from my original post.

I had originally planned to get this accomplished the first week of August. Unexpectedly my MIL became ill and not long after passed away. After dealing with all that's involved in that situation, I was finally able to put this project back on the front burner. I already had everything I needed parts wise, it was just getting psyched up again to deal with the pan removal due to the exhaust cross-over pipe. I re-watched a lot of the videos on how others dealt with this issue until I was ready to tackle it. So I put the truck up on my ramps, gathered all the tools I would need to ratchet the exhaust down, jack the transmission up etc... I removed all the pan bolts except the two under the exhaust, and I loosened those two, so I could drain the most ATF I could to lessen the mess I was sure I was going to make. I finally remove the last two bolts, expecting the pan to drop and catch on the exhaust pipe like every video I saw, and it fell right off into my catch pan.

There was obviously just enough space between the exhaust pipe and the pan for it to clear. I can't describe the elation I felt with that outcome. It still made for a nasty cleanup but I gladly tidied up afterwards knowing I didn't have to fight the exhaust. I must be one lucky fellow.

If anyone is wondering what fluid I used, it was:

https://www.chevronlubricants.com/en_us/home/products/havoline-full-synthetic-multi-vehicle-atf.html

I had planned on doing a flush via the atf return line but decided to just replace the filter and refill since I had my new drain plug welded onto the pan. I buttoned everything back up and took my wife for a 60 mile round trip run to the grocery store. Transmission shifted nice and smooth. Now I have a question. I replaced exactly 7 quarts with the pan drop. I can now easily drain the pan and was wondering if 60 miles is a long enough drive for me to do another and remove even more of the old fluid. If I do drain another six quarts out and replace it, how much of the old fluid will remain? The transmission holds approximately 12.2 quarts.

 

[ArrestMeRedZ]

I should know better than to do math in public, but to two places, 21% or 2.6 quarts of old fluid remain with a 7 quart then a 6 quart replacement. This assumes 6 quarts are drained the second time.

 

[Gebo]

made mistake

 

[Gebo]

 

[ArrestMeRedZ]

Nope, did it again. The question was how much old fluid remains.
First change was 7 new quarts, leaving 5.2 quarts of old fluid in the transmission. The ratio of old fluid was 5.2/12.2 or 42.62%. The next change removed 0.4262 x 6 = 2.6 quarts of old oil. 5.2 - 2.6 = 2.6 quarts of old oil remaining.
Your spread sheet was improperly used, or is incorrect for the application of two changes.

 

[Snagglefoot]

I wonder what the filter looked like inside. Any plans to cut it open?

 

[greg_J35]

I realize you are dealing with a GM however, with my F150 and Honda, I do a simple drain and fill every other oil change which is approximately 10k miles. Both vehicles have over 200k miles with original transmission that performs great.
On the F150, I do a filter change every 100k miles.

 

[Sierra048]

I didn't cut the old filter open. Unfortunately it's been recycled. I never thought about looking inside it.

I can tell you that I was extremely happy to see very little residue on the bottom of the pan and the magnet compared to the videos I watched. The truck had 50,104 miles on it when I did it this past Sunday. It was better than I anticipated.


"I realize you are dealing with a GM however, with my F150 and Honda, I do a simple drain and fill every other oil change which is approximately 10k miles. Both vehicles have over 200k miles with original transmission that performs great.
On the F150, I do a filter change every 100k miles"

Now that I have a drain plug installed, and after I try to get most of the original fluid out now, I will follow the same regimen I do with my wife's Frontier, a drain and fill every 25k.

ArrestMeRedZ,

Thanks for the math.

 

[nthach]

I think you've done better than 90% of people with dropping the pan and replacing the filter just to get the break-in contaminants and normal wear sludge out. The OEM Filtran filters might not look like much but they can hold a good bit of dirt before flow starts to slow down.

Did you use another OEM filter?

 

[Sierra048]

I'm a maintenance fanatic. Besides, as a retiree it gives me something to do. Yes. I bought a genuine AC Delco replacement filter.