Ford 6R80 transmission fluid changes

[Elroy the Brave]

There are very few transmissions on the market that are so special that a commonly available fluid on the market won't surpass the performance of the OEM fluid. So many people think their transmission (or other component) is "special" because the mfg has stated as such but this very rarely turns out to be true. We hear it all the time, every year, for decades now.

I've never used Liqui Moly products but I'm sure if they have an appropriate fluid for your application then it would work well. I know from decades of experience (and the visible lack of published articles / lawsuits / etc) that fluids from reliable brands perform as advertised. Red Line, Amsoil, Valvoline, Mobil and even the off/store brands (OEM, MotoMaster) have never disappointed. I HAVE seen several issues that were misdiagnosed / misunderstood and were blamed on fluid BRAND and not on the fluid condition / maintenance history / electrical issue / unknown TSB.

In my most recent case, our warranty replaced CVT transmission was being actively destroyed by the firmware in the TCU that was to be updated at the time of replacement, but was not. I was able to figure this out myself, after a few years, but no amount of maintenance, service or fluid swapping was going to correct the failures of Nissan the Nissan dealer. I contacted ~ 10 dealers in my area and NONE of them were able to explain this to me or to suggest a course of action other than to order a new CVT replacement.

TLDR, high performance transmission fluids are readily available, your transmission does not require a special fluid and supporting your OEM dealer is probably a bad idea.

Agreed. In fact, I've experienced improved, smoother shifting switching to some aftermarket transmission fluids. Installed Redline C+ in a Chrysler once, and it dramatically improved the shift quality of a car.

More recently I have had good success will Valvoline Extended Performance ATF and will be trying out Valvoline Restore and Protect ATF on a Ford Fusion with the problematic 6F35.

 

[SureshR]

There are very few transmissions on the market that are so special that a commonly available fluid on the market won't surpass the performance of the OEM fluid.

Ok so I somewhat misspoke. What I used for this car was a different European brand, Motul ATF-VI, which claims to fit both Mercon LV as well as ULV, so viscosity probably at a borderline that matches both LV and ULV, which might be fine for a temperate climate like in France but was a bit too thin for tropical India?

FORD MERCON LV, MERCON ULV, WSS-M2C922-A1, XT-10-QLVC, XT-6-QSP (SP)

https://azupim01.motul.com/media/motulData/DO/base/ATF_VI_DE_en_FR_motul_19290_20211231.pdf

 

[Impatient]

Wow. Motul is well-respected around here, but I have zero experience or even hearsay about their ATF.

This is my suggestion, but I am not a guru: more or less repeating what I suggested before: Assuming you still have 10qts of OEM Mercon LV, and assuming you can buy additional for $13-14 per qt, I would stick with OEM, do a 2-time drain and fill: 1st: 4 qts thru dipstick port, to avoid double pan drop, then 2nd the pan drop with cleanup & filter a couple weeks later AFTER you have gotten your used fluid analysis results back. I doubt it matters much which you do first vs 2nd, but take that sample!!! If that doesn’t fix you up for another 25K, then something more major is wrong. And the only hearsay I have re the transfer case is they are super finicky (I don’t have 4wd/AWD, so no direct experience). I can’t download that calculator, but I think after both of these drain and fills, you will still have nearly 5 qts of old fluid. Doing another (3rd D&F) may get you effectively down to 3.5 QTs of old…diminishing returns.

The Motul is red, and the OEM is red. When you drain and sample, if the fluid is not “pretty” red, it’s further proof the current fluid is either tired, or contaminated. Hearsay and experience is OEM does darken with time, but ugly brown, or funny smell are not good signs.

I better duck out, as I don’t really know anymore than what I have already stated (twice).