Mercon Fluid Alternative 4R100 Transmission

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I have a 1998 Ford Expedition with a 4R100 Tranny with 140K miles. It has been dealer serviced at 60K and 90K using Factory Spec XT-2-QDX.
Now I want to change the filter and fluid and cannot find Ford or Motocraft Mercon XT-2-QDX.
I have spent days reading reviews and talking to Ford dealers.
Original spec says DO NOT USE MERCON V, otherwise serious damage will occur. Now Ford says that Mercon V is the new spec and has TSB to back it up. But I have read posts that the damage will not occur for for 30 or 40K miles. Did Ford change the formula in the Mercon V so now it is compatable, or are they selling what they own?
On top of that I read, not to mix Mercon and Mercon V, so I am concerned that even a flush will not get rid of all old Mercon and that power flushes on high mileage transmissions are also very bad.
I feel like using and aftermarket Mercon/Dex3 is the safest most foolproof option, but then which one?
Anyone with any experinces good or bad regarding this subject?
 
Formula has been changed a couple times over the years. It is now compatible.

You can mix Mercon and Mercon-V. No worry there.

You can use any generic Dex/Merc fluid too.

I prefer and recommend the full synthetics.
 
So which do you feel better about? Switching over to Mercon V or using an alternative Mercon/dex3 blend?
I am doing this as preventative maintenance since I do a lot of towing (about 4-5K lbs)
I am mostly concerned about the long term effects of switching to the Mercon V, and equally concerned about the quality of the alternative blends, since they say they are "specially formulated for use in...."
It seems like the blogs I have been reading are about 3 years old, so if there was any adverse effect to switching over, we would have heard about it by now, same is true with using the blend.
 
I have a 99 Expedition with this same transmission.
I did a line off exchange with Amsoil ATF and had zero problems in 45K,i will run a 50K OCI.
Amsoil ATF also works well in the transfer case even at below zero temps,the shift motor engages instantly.

I normally don't push any brand of oil but in this case
Amsoil ATF really works well.

BTW a line off on this truck is child's play,there is a rubber line from the cooler near the R/F,20 min job.
 
Originally Posted By: Trav
I have a 99 Expedition with this same transmission.
I did a line off exchange with Amsoil ATF and had zero problems in 45K,i will run a 50K OCI.
Amsoil ATF also works well in the transfer case even at below zero temps,the shift motor engages instantly.

I normally don't push any brand of oil but in this case
Amsoil ATF really works well.

BTW a line off on this truck is child's play,there is a rubber line from the cooler near the R/F,20 min job.


+1
MERCON V will work well for you. Do a complete flush yourself. Regular MERCON isn't supported by FORD anymore.
 
Have had good results with Valvoline Maxlife Mercon/Dexron in a Mercon application in a 2005 Mariner SUV. It is a synthetic base and very happy with the results. Vehicle has 60K and have done a drain and fill at 20K and 40K and about to do another.
 
Everyone seems to have an different opinion on this, but here is my experience.

My '99 F350 has been running Merc. V fluid for a few years with no problems. Our Navigator has been running AMSOIL ATF for the last 25,000 miles with excellent results as well. The F350 is a plow truck and has towed some heavy loads, and the Navigator has done its share of towing as well.

Thankfully your transmission has been service a few times. I would use the Mercon V fluid without fear.
 
Since we are on the subject of Mercon V. My 2004 Lincoln LS power steering specifies that Mercon ATF be used. Could I use Mercon V ATF in the power steering now?
 
Any feedback on the best way to flush out as much of the old fluid as possible?
4R100 tranny
 
What tranny do you have in your F350?
This gives me confidence to actually hear someone who did the switch without any problems over years under heavy service.
How many miles would you say it's been since your last change to the Mercon V?
 
Originally Posted By: Fitz98
Any feedback on the best way to flush out as much of the old fluid as possible?
4R100 tranny


I pulled the return line off the tranny, and did it 6L at a time that way, which gets it all out.

I found I had firmer shifts with Mercon vs Mercon V (I have used both). Whether that would have had an effect on tranny life? I doubt it.

I drive it VERY hard however.
 
So you drain 6 from the return line, put in 6 to replace, drain another 6 and so on? I am assuming that the new fluid pushes the old and they don't actually circulate and mix during the process.
 
Originally Posted By: Fitz98
So you drain 6 from the return line, put in 6 to replace, drain another 6 and so on? I am assuming that the new fluid pushes the old and they don't actually circulate and mix during the process.


Correct. It is a two person job. Have a friend fire it up, let the tranny pump out 6L (it will start to sputter at the return line at this point) and then shut it off. Dump in 6L. Repeat. You will notice a change in the fluid colour when new fluid starts coming out. This took place after putting in 18L on mine, which is the capacity of the system. So buy 20L to be safe, as you will have to top it back up when you are complete.
 
Thanks for the article. In this scenario, it appears as if you actually run the system dry, before re-filling, instead of remove part, replace part, remove part and so on. Is that correct,or am I misreading it?
 
http://www.amsoil.com/faqs/ATF_and_Filter_Change_Procedures.pdf

Here is another way.

I did it this way, as Amsoil suggested. I just did discover the popular mechnics link until a few days ago. The downfall to the Amsoil method is that you could possible flush contaminents into the new fluid. I did it 2 quarts at a time where I flushed into a clear container and refilled the fluid. There was no way that I could get the fluid into the dipsitck as quick as it was coming out. I also had a transmission with a fluid coapcity of 8 quarts.

The only problem with the other way would be that you shoudl probably add a few quarts to make sure some old fluid doesn't get stuck in. I read another Cadilac formun where someone only got as much fluid to come out as a basic pan drop.

The other link avoids contaminated a new filter. If I missing anything, someone let me know. My kids want me to take them on a wagon ride.
 
Originally Posted By: Letter_K
http://www.amsoil.com/faqs/ATF_and_Filter_Change_Procedures.pdf

Here is another way.

I did it this way, as Amsoil suggested. I just did discover the popular mechnics link until a few days ago. The downfall to the Amsoil method is that you could possible flush contaminents into the new fluid. I did it 2 quarts at a time where I flushed into a clear container and refilled the fluid. There was no way that I could get the fluid into the dipsitck as quick as it was coming out. I also had a transmission with a fluid coapcity of 8 quarts.

The only problem with the other way would be that you shoudl probably add a few quarts to make sure some old fluid doesn't get stuck in. I read another Cadilac formun where someone only got as much fluid to come out as a basic pan drop.

The other link avoids contaminated a new filter. If I missing anything, someone let me know. My kids want me to take them on a wagon ride.


The system on the 4R100 (and I'm sure most other trannies with a cooler) is a loop.

The fluid leaves the pan, goes through the entire system before ending up back in the pan via the return line.

By removing the return line from the transmission, you are preventing any old fluid from going back in the pan. The pan on the 4R100 holds 6L.

When you get ~6L out, you will start getting air (sputtering) from the return line. This is when you shut it off. This indicates that the pan is empty.

Refill through the dipstick tube, which fills the pan. Add 6L. When you start it up again, the next 6L in the system is displaced out the return line. The first 6L of new fluid is now starting its way through the system. You do this until all the old fluid is removed, which, as I said, is around 18L. This takes three start/stop cycles to complete.
 
Perfect answer. Thanks.
I think I have the flush proceedure locked in now.
Where in Ontario do you live? I moved to Fla, from Grand Bend (close to London)
 
Originally Posted By: OVERK1LL
Originally Posted By: Letter_K
http://www.amsoil.com/faqs/ATF_and_Filter_Change_Procedures.pdf

Here is another way.

I did it this way, as Amsoil suggested. I just did discover the popular mechnics link until a few days ago. The downfall to the Amsoil method is that you could possible flush contaminents into the new fluid. I did it 2 quarts at a time where I flushed into a clear container and refilled the fluid. There was no way that I could get the fluid into the dipsitck as quick as it was coming out. I also had a transmission with a fluid coapcity of 8 quarts.

The only problem with the other way would be that you shoudl probably add a few quarts to make sure some old fluid doesn't get stuck in. I read another Cadilac formun where someone only got as much fluid to come out as a basic pan drop.

The other link avoids contaminated a new filter. If I missing anything, someone let me know. My kids want me to take them on a wagon ride.


The system on the 4R100 (and I'm sure most other trannies with a cooler) is a loop.

The fluid leaves the pan, goes through the entire system before ending up back in the pan via the return line.

By removing the return line from the transmission, you are preventing any old fluid from going back in the pan. The pan on the 4R100 holds 6L.

When you get ~6L out, you will start getting air (sputtering) from the return line. This is when you shut it off. This indicates that the pan is empty.

Refill through the dipstick tube, which fills the pan. Add 6L. When you start it up again, the next 6L in the system is displaced out the return line. The first 6L of new fluid is now starting its way through the system. You do this until all the old fluid is removed, which, as I said, is around 18L. This takes three start/stop cycles to complete.


Looks like a much better system. I was always worried that running air in the system might cause problems. Is there a certain amount of time you should let the system idle? I'd imagine that air would work it's way out pretty quick. As in while you are idling and getting fluid levels up to the correct spot on the dipsitck.

So based on the diagram you present of fluid moving through the system, you could do your pan drop first, get the 6L out of the pan, change the filter, add 6L to fil the pan and pull the cooler lines and flush 2 more time at 6L each to replace the total 18L. You could do an extra L or two just to be safe.

No damage should occur if you stay in park and cut the engine once you see any sign of air? Correct?
 
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