1998 Ford Windstar transmission shudders

[txangel78]

My transmission has started to shudder when it downshifts. So far it does not do this around town at lower speeds, only when I am driving on the interstate or such. Also I have noticed that if the a/c is not on this usually doesn't happen. The vibration only lasts for a few seconds after each downshift and it feels like you are going over railroad tracks or speed bumps. I have read some articles that say this problem might could be fixed by taking the vehicle to a shop and having the trans. fluid completely flushed, refilled and changing the filter. I have five children and cannot afford costly repairs, but I also depend on this vehicle daily for transportation. I am planning to make an appt. to have a diagnostics test run, but I would appreciate any ideas or input before I do this so that I will have an idea of whats really wrong and wont pay for something that I do not need done.

[ModMech]

Our '98 does the very same thing.... when the ATF gets old.

Now, I advise you NOT to have a COMPLETE transmission fluid flush, because under some common conditions you can actually cause the trans to fail if the fluid is very old or burned. You can definately have only the pan drained and the filter replaced, but the cost at about $85 is the same either way.

Your van's transmission NEEDS a special type of ATF called "Mercon V" (Mercon 5), and many shops are not aware of this.

Should you elect to have your filter changed, and the fluid in the pan replaced (that would be about 1/4 to 1/3 of all the fluid), you also want to have the mechanic disconnect the battery for 15 minutes or so while they are perforing this. That will tell the computer than you put new fluid into the trans, and this should help it shift better and last a good long time.

[txangel78]

Thank you so much for the reply. I feel better knowing someone else has fixed the problem with some routine maintenance. If that is the case, then would it be ok to just do this ourself and save the mechanics fee? Will I notice the difference soon? In the articles I read it said you might have to drive it a few hundred miles before you can tell. Will the store brand fluid (such as autozone's) work or should it be the name brand? Also, you said to use Mercon V but some other posts said that if it was manufactured before 09/97 it would use just Mercon. I checked and mine was made in o6/97 and the dipstick says Mercon not Mercon V.

[SamNovice]

I had the same problem with my 98, but it happened when the car was new. As you said, it occured most after a high way driving (for the first few times, I thought I hit bad potholes). I took the car to a dealer but they claimed they could not reproduce the problem. I decided to ignore it and for some reason the problem disappeared after a couple of years.

[MT-2500]

Originally Posted by txangel78

Thank you so much for the reply. I feel better knowing someone else has fixed the problem with some routine maintenance. If that is the case, then would it be ok to just do this ourself and save the mechanics fee? Will I notice the difference soon? In the articles I read it said you might have to drive it a few hundred miles before you can tell. Will the store brand fluid (such as autozone's) work or should it be the name brand? Also, you said to use Mercon V but some other posts said that if it was manufactured before 09/97 it would use just Mercon. I checked and mine was made in o6/97 and the dipstick says Mercon not Mercon V.

txangel78 you are sharp on that.
Good find on the mercon on dipstick which is dexron111 now.
Yes the 98 and even 99 windstar AX4S transmission takes mercon/dexron111
The dip stick is the best place to check for what kind of fluid to use.
Also Autozone and some other parts places give free code checks.
Good Luck
MT

[wiswind]

The TSB number is 01-15-7, released on 08/06/2001 by FORD.
It DOES say NOT to use Mercon V in 1998 Windstars built before 9/09/97.
The TSB says Mercon and Mercon V are NOT interchangable.
Do NOT use Mercon V in a vehicle that calls for Mercon.
Do NOT use a fluid that indicates that it is "dual usage" for Mercon and Mercon V in a vehicle that calls for Mercon.

Within the past year, Mobil 1 ATF, which is shown being used in my pictures for my '96, has changed to state that it is both Mercon and Mercon V.
This was not the case when I did my fluid change last fall.....at that time, it was listed as only Mercon.
So, from what the TSB states, the new Mobil 1 would NOT be an acceptable fluid for use in your pre-Mercon V vehicle.
I am not qualified to recommend anything outside of what the manufacturer has stated in their TSB, so I will not make any recommendations outside of what is stated there.

You can get the Mercon ATF at the dealership, if you cannot find it at a parts outlet.
Be very persistant, and read the label......if it is Mercon rated, it will say so on the label.
If you can find a synthetic Mercon, that would be even better.

The pictures of my fluid and filter change are a complete fluid change, which I do once a year.
This year, I plan to buy Redline ATF from www.myoilshop.com for just over $7 per quart, plus shipping.

[MT-2500]

Originally Posted by wiswind

The TSB number is 01-15-7, released on 08/06/2001 by FORD.
It DOES say NOT to use Mercon V in 1998 Windstars built before 9/09/97.
The TSB says Mercon and Mercon V are NOT interchangable.
Do NOT use Mercon V in a vehicle that calls for Mercon.
Do NOT use a fluid that indicates that it is "dual usage" for Mercon and Mercon V in a vehicle that calls for Mercon.

Within the past year, Mobil 1 ATF, which is shown being used in my pictures for my '96, has changed to state that it is both Mercon and Mercon V.
This was not the case when I did my fluid change last fall.....at that time, it was listed as only Mercon.
So, from what the TSB states, the new Mobil 1 would NOT be an acceptable fluid for use in your pre-Mercon V vehicle.
I am not qualified to recommend anything outside of what the manufacturer has stated in their TSB, so I will not make any recommendations outside of what is stated there.

You can get the Mercon ATF at the dealership, if you cannot find it at a parts outlet.
Be very persistant, and read the label......if it is Mercon rated, it will say so on the label.
If you can find a synthetic Mercon, that would be even better.

The pictures of my fluid and filter change are a complete fluid change, which I do once a year.
This year, I plan to buy Redline ATF from www.myoilshop.com for just over $7 per quart, plus shipping.

All mercon fluid has been fazed out.
It has been replaced by dexron 111 ATF
mercon/dexron 111 is a non synthetic fluid.
Transmissions made for mercon/dexron 111 do no do well on sythethic fluid.
Use only dexron 111 in them.
MT

[txangel78]

I just wanted to say a quick thanks for all your suggestions. My husband changed the fluid and filter and that seems to have corrected the problem. I just bought the vehicle a year ago so who knows when the last time it was changed, if ever!!

[wiswind]

I have the old version of the Mobil 1 ATF, Mercon / Dextron III in my '96, which calls for Mercon.
The Mobil 1 is Synthetic. I did read that the Motorcraft Mercon V is Synthetic....and that Mercon can be found in synthetic and conventional forms.
The Mobil 1 has done great in my transmission for several years.
I have checked Alldatadiy to see if they have gotten a TSB from FORD saying different from the one that I listed.
I am not qualified to advise other than what FORD has stated, which was that a vehicle that calls for Mercon should NOT have Mercon V or a fluid that claims to meet BOTH Mercon and Mercon V specifications.....or "transmission damage may result".
Dextron, is a GM specification.
Mercon is a FORD specification.

I have read of people using dual specified fluid with success, but going away from the FORD recommendations has to be a personal choice, carefully made.

[chasealley]

Just a quick note....

I read recently that Ford is going to stop granting licenses for other manufacturers to make Mercon....I believe the date was April 2007. They are trying to encourage them to make Mercon V which is supposed to be better. I have a Mercon V car and I can't answer how this will affect the Mercon people. I assume that Ford will either make Mercon only under their own brand, or they will issue a new TSB instructing you which to use in place.

This is probably a good move because when I changed my Mercon V recently I had to go to the dealer because I couldn't find ANYONE who carried it. One parts place told me "Mercon V isn't popular enough." Now I don't want to be a stickler, but what about all those cars made since 2000 that are supposed to use it?? Either they are getting serviced at the dealer or not at all. And with the amount of chatter about bad Ford transmissions I'd have to assume it is probably just people not doing the service at all. But here is the thing. If I check my trans at the service station when I get gas and it is low, what do I use in place? Something labelled "Mercon V compatable." Which means I'm spoiling my Mercon V by adding half a quart here and there.

Moral or the story. If you buy a Ford, ask what the previous owner did for transmission service

[wiswind]

Yes, Mercon V has been very difficult to find.....and the newer FORDs use Mercon V......so as mentioned......Mercon will become harder to find.
They may issue a TSB stating to use Mercon V.....I was expecting that when Mobil 1 went from just Mercon to Mercon and Mercon V....as they are a pretty big and reputable company.
I am suprised that it has taken so long for the Mercon V to become readily available, given the recommended change interval, and the number of units on the road that call for it.

I spent about $2800 on a tranny several years ago.......and I don't want to end up leading anyone down a path to a bill like that.....which is why I am being very specific about what FORD has said.

I have read the TSB on alldatadiy that says that the 5W-20 oil is acceptable for use in my '96 3.8L windstar.......which was originally specified for 5W-30 oil.
So they seem to get the updates as they come through.

[chasealley]

Originally Posted by wiswind

I am suprised that it has taken so long for the Mercon V to become readily available, given the recommended change interval, and the number of units on the road that call for it.

Yes, I believe Ford is surprised about that too from what I understand, and that is the reason for not granting the Mercon license any longer. I guess they are trying to get the manufacturers to make the Mercon V because Ford believes it is a better product. I'm curious for what reason Big Oil has kept away from it? Maybe tighter tolerances and increased cost? I know I paid about $100 CDN for oil for my trans at Ford. Expensive. But yes, I too had to do a transmission (in a Corvette and had a racing TC) so I'd prefer not to have to do that again Everyone changes engine oil but most forget about trans.

Preventative maintenance is a very good thing.

[Riordan3]

Guys,
Autozone and Advance Auto Parts carry the Mercon V in my area. Worth a peak if you have these stores in your area. I just bought Castrol Brand Mercon V for around 4 dollars a quart.

[Ed_Strong]

I found Castrol Mercon V ATF at Walmart for $3.49 a quart. Couldn't find it being sold by the case tho, that would've been cheaper!