2005 Ford Escape 4wd
Transmission was rebuilt around five years ago.

My wife said last week, the transmission slipped on her way home from work, so I checked the fluid level. It was at the bottom of the hash mark, so I drove it the next morning and bought a quart of fluid. The car behaved normally for this trip.

The online bot for one of the chain auto parts stores listed 33 results "Recommended For Your 2005 Ford Truck Escape 4WD". Included among them were both Mercon V and Dex/Merc combinations. Another chain store's bot offered only two "exact fits", both of which I considered a superior brand on sale for about the same price as the "lesser" at the first chain. I obviously didn't pay a lot of attention to the particulars of the second store's suggestion, probably because I had spent so much time looking at the first store's 33 results.

Next morning I popped into the second store and because all of the Castrol transmission fluids were on sale, I picked up a Dex/Merc because I figured it matched the plain "Mercon" written on the top of the dipstick and the first store's website had specifically included it among those recommended for my vehicle.

When I got home, checking the level a couple of times as I added, I put the full quart in the Escape. I thought it may have been half a pint too much, but I went ahead and added the last bit. Later that day I drove a seven mile roundtrip with no problem, but then my wife drove it on an errand about twice as far, came home and said it was much worse than it had been before. She said that a couple of places, it was like the car wasn't in gear, so I took it around the neighborhood and found it needed a little coaxing in spots (at 20mph) and the O/D light started flashing as I drove around the block.

When I got home I checked the fluid and it registered way overfull, so I used a siphon pump to take out about a pint, which put the dipstick within the hashmarks. The only other time I drove it Saturday, after siphoning from the dipstick tube, the SUV behaved normally.

Today (Sunday), we drove it to the next town to a festival 15 miles from my driveway. About twelve miles down the road, the vehicle clunked into gear a couple of times, slowing or starting from a stoplight and the O/D light flashed like there might be a sensor issue, but otherwise it worked fine in city traffic and after a couple of hours rest at the festival, it drove fine for the fifteen miles home.

Then later I took it out again and about twelve miles from the house, the O/D light started flashing and the car quit going. I pulled into a parking lot, turned it off and restarted it a couple of times until it'd go into reverse, then it went forward enough for me to get it back on the road, then it pretty much quit going forward and acted like it was in neutral. After stopping for maybe five minutes, I started it up again to get it to a better parking spot and it did fine for about a hundred yards, then it didn't want to go any further, so I left it parallel parked on a residential street.

I now see, after looking through this forum and a couple of other sites, Dex/Merc isn't the same as Mercon V and after looking at the back of the container I bought, 2005 isn't listed as one of the years for that transmission fluid and it explicitly says it's not the same as Mercon V.

Armed with all of that information, my usual over-explanation, do you think I could get by with just draining the transmission fluid and refilling with the right product or will I need to flush the system?

All told, the vehicle was driven less than a hundred miles -- if my math and memory is correct, about 75 miles -- with one quart of the wrong fluid.

Does anyone think I'm on the wrong track, choosing between changing and a flush?

Thanks for any and all help.

 

Did you use the right level-check procedure? IIRC it calls for the level to be checked with the transmission warm and in Drive for the measured level to be correct, did you do this? If not it may primarily be a level issue and not a contamination issue - although I don't know what the chemical effect would be of combining the two fluids in that ratio.

 

The Mercon isn't the problem, the transmission originally left the factory filled with it. More likely than not, the rebuilder/installer used Mercon V five years ago. Adding some Mercon as a top-off isn't going to harm anything, it's just that the added fluid doesn't have the same improved characteristics as the Mercon V which presumably was used.

The problem is that it's a CD4E transmission and it's likely on its way out (again) as indicated by the initial report of slippage. Neither a flush nor a drain is likely to change the outcome.

 

That's exactly right. The Dex/Merc didn't cause the problem, and won't hurt your trans.

 

That's not what I need to hear. My wife has wanted to sell the vehicle for years because it's had several expensive repairs. I've put her off because the motor has always worked fine and I've never heard of having to rebuild a transmission twice. (Actually three times, but the second was under warranty from the first rebuild, so it didn't cost)

Previously, I don't remember the O/D light being involved and the first failure was much more gradual than what happened this time. There were indications that the transmission was going out for weeks, multiple times it didn't want to go, not a hundred miles from the first symptom to fail.

I believe that I initially siphoned cold, then drove it on a ten mile loop and siphoned the rest of the pint with everything warm. I then put it through the gears on the gear shift like ten minutes after my ten mile loop and checked with the engine running, in park.

If your suggestion is the case and it's a viscosity issue. Theoretically it might work enough from the cold park for me to get it home and not have to drain the fluid in a shopping center parking lot or on the side of the street.

One other factor which may or may not have any bearing, but as I mentioned in a previous post when the ball joint went bad, a mechanic removed the drive shaft because he says it was bad and we don't really have a need for the 4wd aspect anymore.

 

Update: After letting it sit overnight (14 hrs), we started it up and it went good for maybe half a mile, then it wanted to go no further. Pushed it into a parallel parking spot and barring anyone or any web search making a suggestion other than it's a bad transmission, we're weighing whether to fix it for sale or to sell it as-is.

I'll keep a check on this thread.
As always, thanks.

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ETA: Of course now that it's in my driveway, part of me wants to change the transmission fluid just to see if that'll do the trick, but even though a jug is comparatively cheap, I'm not really wanting to spend any more on this vehicle, if it's unlikely to do any good. Again, thanks.