Best fluid for partial drain + fills for Ford CD4E

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My 2003 Mazda Tribute has the Ford CD4E transmission in it.
This tranny has a drain plug that allows you to drain about 3.5-4.0 quarts of fluid out of the tranny at a time for partial tranny fluid replacements.

Tranny calls for Mercon fluid, which is still fairly easy to get. I know there are possible issues with mixing Mercon and Mercon-V fluid, so aprtial drain and fill should use Mercon fluid.

What I'm wondering about is the 'multi-vehicle' ATF's you can get, either full-syn ones, like Amsoil or Mobil, or the partial syn ones, like Pennzoil or the ST's in Canada sell a syn-blend multi-spec fluid. A partial-syn one is what I'm thinking of using.

These fluids all say they meet many specs at once - like Dex-III and VI, and Mercon and Mercon-V. If I am doing a partia drain and fill, would I be better to stick to just a Mercon fluid, or would I benefit by upgrading a bit to a partial-syn multi-spec fluid?

Do you think mixing Mercon, and a multi-vehicle ATF would cause the exact same problems as mixing Mercon and Mercon-V?
 
Why do you think mixing Mercon and Mercon V causes problems? It doesn't. Any transmission that originally speced Mercon can now use Mercon V without problems.
 
Addy, I think you should just use a Mercon fluid the same spec you have in right now. Transmissions are just too problematic to mix fluids. If you have a fairly regular drain method like this the Mercon should be absolutely fine.


Just my conservative opinion. I don't think it would kill anything but it isn't necessary.
 
Last edited:
Originally Posted By: exranger06
Why do you think mixing Mercon and Mercon V causes problems? It doesn't. Any transmission that originally speced Mercon can now use Mercon V without problems.


Because mixing Mercon V and Mercon HAS caused failures in CD4E transmissions, at least in earlier CD4E's with earlier Mercon V formulations.

I 'think' the problem has been fixed now...but there is still some debate. I'll most likely just stick to a quality Mercon fluid, I really can't afford to have the tranny fail.
 
I don't think mixing fluids causes the CD4E to fail; the CD4E being a very bad transmission causes it to fail.

Make sure to get the older Mercon out and refill with Merc V and install the largest transmission cooler you can.
 
Just follow the procedure for completely changing out the trans fluid. It's not that hard. Easier than replacing a transmission.

Quote:
Tools required: pliers, 10mm socket, milk jug, transmission fluid funnel
Parts required: 1 case of MERCON transmission fluid
Optional: get a new 1/2" screw-down hose clamp to replace the cheap factory hose clamp.
Drive car up on ramps.
Remove the drivers-side black plastic underbelly pan (held on with several 10mm bolts). This exposes the 2 hoses running to the transmission from the transmission cooler. There are 2 black rubber hoses running from the external transmission cooler in the front of the car. Each one attaches to a metal tube that attaches to fittings on the transmission. The tube attached to the front of the transmission is the outlet (i.e. fluid is discharged from the transmission here). The fitting in the rear of the transmission (and also closest to the front wheel) is the inlet (i.e. fluid enters the transmission here). To flush the transmission and the external cooler, you need to disconnect the rubber hose from the metal pipe that connects to the rear of the transmission (the inlet).
Identify the transmission inlet hose, and remove the hose clamp with pliers. Pull the rubber hose off of the metal pipe. Some fluid may come out, but there won't be much. The idea of a transmission fluid flush is to use the transmission's own pump to pump out old fluid, and then replace it with new fluid. I used a 1-gallon milk jug to collect the old fluid, and a helper to start and stop the car's engine on my command.
Position milk jug under disconnected inlet hose, and have helper start engine. Fluid will pour out of the inlet hose into the milk jug. Stop the engine when approx 2 quarts have come out (the milk jug is 1/2 full). This will take 15-20 seconds or so.
Add 2 quarts of new transmission fluid into the dipstick tube.
Repeat steps 4 and 5 until the transmission fluid coming out is the same color as the new fluid. For me, it took a full case (12 quarts) of fluid. At least one time during step 4, have the helper shift the transmission into R and D while the engine is running. When all fluid has been replaced, reconnect the rubber hose onto the metal pipe and install a new screw-type hose clamp (the factory clamps are junk).
 
I had a 2002 626 for a minute with that transmission and I was thinking about doing the same thing you're thinking about doing. I did lots of research here and elsewhere and decided against it.

I called my local dealer and asked him about it and, he told me I'd be better off not doing anything at all. His explanation was, the wear inside the transmission generates abrasive particles that actually cause friction that allows the tranny to work ok. If the fluid, along with the particles, is changed, the transmissions sometimes fail.

Just passing along what I was told by a certified Mazda mech.

This was just a bad period for Mazda.
 
Originally Posted By: suspiciousmind
I had a 2002 626 for a minute with that transmission and I was thinking about doing the same thing you're thinking about doing. I did lots of research here and elsewhere and decided against it.

I called my local dealer and asked him about it and, he told me I'd be better off not doing anything at all. His explanation was, the wear inside the transmission generates abrasive particles that actually cause friction that allows the tranny to work ok. If the fluid, along with the particles, is changed, the transmissions sometimes fail.

Just passing along what I was told by a certified Mazda mech.

This was just a bad period for Mazda.

That myth applies to any automatic transmission, not just Mazdas. And that's all it is: a myth. It is always better to have fresh clean fluid in a transmission. I definitely don't want any "abrasive particles" in my transmission. If the clutch packs are so worn they can't hold any more, the transmission needs to rebuilt. Leaving "abrasive particles" in the fluid to hold it together is not a proper fix.
 
The "driveway flush" is all we do anymore for fluid change. So easy and so quick.

No need for any expensive equipment. Just not it is NOT a substitute for an occasional pan drop and filter change.
 
I have a 2001 (very early build in 2000) Ford Escape 3.0 V6 with 188,500 miles and just changed the transmission fluid 3 weeks ago. Before I always used Mercon but could not find it this time but noticed that Castrol Mercon V label states that it is certified for use in Ford that require Mercon. Have about 1000 miles since the change and the only change I see is the shifts are just a little bid smoother. I did replace the old fluid and a day later drained it again to get a more complete flush.
 
Originally Posted By: Desertdog
I have a 2001 (very early build in 2000) Ford Escape 3.0 V6 with 188,500 miles and just changed the transmission fluid 3 weeks ago. Before I always used Mercon but could not find it this time but noticed that Castrol Mercon V label states that it is certified for use in Ford that require Mercon. Have about 1000 miles since the change and the only change I see is the shifts are just a little bid smoother. I did replace the old fluid and a day later drained it again to get a more complete flush.


Thanks very much for the info. I 'think' the Mercon/Mercon-V compatability problems have been completely fixed with a mild re-formulation they did a couple of years ago.

I have read on Escape City that many, like you, are mixing the two without issue now. I still will most likely play it safe....
 
I've seen two different sites which claim using Mercron V in a CD4E will damage it:

Everything You Need To Know About The Ford CD4E Transmission

Quote:
What kind of fluid should I use in my customers CD4E? Mercron. Please do not confuse this with Mercron V which will damage your customer’s transmission.


Contour Enthusiasts Group CD4E FAQ

Quote:
What kind of fluid should I use, when changing my fluid?
The CD4E is designed to use Mercon. Not Mercon V! This holds across all models years. You can use pretty much any brand of multi-purpose ATF fluid. You will most commonly see it on the shelf labeled as, "DexronIII/Mercon". These multi-purpose ATF's also cover the same specs as Type H, which the CD4E may call for in other countrys. If you want, you can use synthetic based fluids such as, Mobil 1 Synthetic ATF or Amsoil Synthetic ATF. There are of course others out there and I will let you do all that research. I will let you draw your own conclusion in that area on what is best for your CD4E. Just stay with either Mercon or a synthetic variant and you will be fine. And yes, if you want to slowly change over to a syn, by performing the 4 quart drop procedure, you can.
 
Dealer is an id1ot if they think wear causes it to work or stay together. This internet rumor is all over multiple forums. Its a lie.

Transmissions fail when they fail. All you can do is treat it with respect and maintain it.

I would upgrade to a blend or full synthetic ATF. I would use the best Mercon-V that you can find(Redline, Amsoil, Mobil1, RoyalPurple).

https://www.fcsdchemicalsandlubricants.com/main/quickref/atf.pdf
CD4E calls Mercon-V from 1997-2008.

CD4E TransGo

CD4E Sonnax
 
Since making this post, I have done a few drain and fills with just the most basic Dex/Merc fluid I can buy; and a cheap can of 'Transmedic' for the heck of it.

Tranny is still alive, although showing it's age, but it seems to respond very well to this combo, running very well after it is installed.

It will be getting another transfusion with this combo fairly soon for the fall/winter.
 
Mag1 makes an affordable fluid that will work. I have the same transmission but I use MerconV.

I don't think mixing Mercon or MerconV is the problem historically for the CD4E. The problem appears to be when the CD4E is paired with a V6. There have been no signs of CD4E issues for those with the 2.0L or 2.3L engines. Apparently the V6 just has too much power for the CD4E if you don't take extra special care of it.
 
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