Ford 6R80 transmission fluid changes

[SureshR]

So I have a 2018 Endeavour (aka the Everest in Australia, basically a Ranger with a 7 seater SUV body) with a 6R80 transmission (ZF + Ford joint dev right?)

Usage conditions - 60% highway and 40% city (bumper to bumper in Indian tropical conditions) traffic.

Changed the original transmission oil at around 60k miles to a liqui moly "universal" ATF that claimed compatibility with Mercon LV and a laundry list of other european, japanese and american standards that it claims the fluid is "recommended" for.

https://www.liqui-moly.com/en/top-tec-atf-1800-p000243.html

Aisin Warner AW-1, BMW 83 22 0 142 516/83 22 2 152 426/83 22 2 289 720/83 22 2 305 396/83 22 2 305 397/83 22 2 355 599/M-1375.4, Dexron VI, Fiat 9.55550-AV5, Ford Mercon LV, Honda ATF 3.1/DW-1/Typ 3.0, Hyundai SP-IV/SP-IV-RR, Isuzu ATF WSI, JASO 1A-L ...

Now, barely 20k miles down the line, I started to get slippage in the transmission, slight jerks when shifting in low gears and such.

Drained as much of it as I could with a pan drop on a warm engine (a bit more than 6 quarts) and refilled with OE mercon LV from a ford parts store. There was very minor debris on the transmission filter so I cleaned the old filter and reinstalled it.

Now, again something like 25k miles down the line and the same thing is cropping up. I take it this claim of being one size fits all isn't quite accurate and the liqui moly is somewhat too thin for the 6R80. So I've got another 10 quarts of Ford OE mercon LV.

Just do another pan drop, drain and refill, so that more of the really old (factory fill fluid) and maybe not as suitable old (Liqui Moly) drains out, or do I do stuff like disconnecting the transmission cooler lines and draining at least a quart more of old oil out besides the 6+ quarts from a pan drop? I'm getting a new ATF filter this time around.

By the way, I of course refilled the transfer case as well, first with the liqui moly and then with the ford OE.

 

[Egg_Head]

How many total miles (km) on vehicle? EDIT: got it 60+20+25= 105k miles
Use this to determine how much of the Liqui moly is remaining. Your tranny takes 13.1 quarts (12.4 liters) at full level:

S

Thread 'Transmission Partial Drain CALCULATOR **Sticky'

Apr 3, 2014

Here's a link to my Partial Drain Calculator Spreadsheet.

You must dowload it for it to calculate for you, it is an EXCEL Worksheet. Dropbox will just show a preview.

I have seen to many people miscalculating the percents and numbers on partial drains and refills on their transmissions.

What folks commonly say is "if I drain 2 of 6 quarts over 3 times, heck I can have a full changeout by the tuird time..BEWARE! That's not the case... because of mixing, it wont be until the 7th fluid change that you actuially reach a 95% total new fluid.

I used university mathmatics people to design...

• SumpChump
• Replies: 28
• Forum: ATF, Differential, Trans, Brakes, P/S

• 

 

[Cujet]

The 6R-80 is very sensitive to fluid type and condition. I suggest installing a drain plug. It is likely you will drain as much as 7 quarts this way. A partial change every 30,000 miles is what worked for me. Always use OEM Ford fluid. The alternatives don't work.

Don't bother with a 'flush' by disconnecting the line. It simply pumps out your new fluid.

One thing you can do is to reset the TCM (transmission control module) properly. It adjusts line pressure and will learn your driving habits. After a reset, do the proper drive cycle. Often helps immensely.

These transmissions are very long lived when maintained carefully. Many of them exceed half a million miles without issue.

 

[martinq]

We have a similar tranny on a 2014 F150. Did you check for service bulletins and have you had the pan off for cleaning? The magnets do most of the important filtering and Ford added extra magnets because of the trouble they were having. Regardless of how many magnets are in the transmission they will not be effective if they are not cleaned.

I know Ford has some updates / recalls for the 2014 6R80 but don't know about 2018.

 

[martinq]

The 6R-80 is very sensitive to fluid type and condition. I suggest installing a drain plug. It is likely you will drain as much as 7 quarts this way. A partial change every 30,000 miles is what worked for me. Always use OEM Ford fluid. The alternatives don't work.

Don't bother with a 'flush' by disconnecting the line. It simply pumps out your new fluid.

One thing you can do is to reset the TCM (transmission control module) properly. It adjusts line pressure and will learn your driving habits. After a reset, do the proper drive cycle. Often helps immensely.

These transmissions are very long lived when maintained carefully. Many of them exceed half a million miles without issue.

OEM fluid is absolutely NOT required or desirable unless it is a "buy it now" deal. The transmissions are sensitive to fluid that is dirty, worn and overheated, not to the brand / label. Keep those magnets clean and monitor your temperatures.