2000 Windstar 3.8L Grabby Tranmission Shift from 1st to 2nd gear.


OldFaithful
01-08-2006, 09:43 PM
The transmission shift from 1st to 2nd gear was grabby and not smooth. There was a fluid leak from the low to intermediate servo cover on the back of the transmission. It is located just above the oil pan on the right back side of the transmission. This servo puts the pressure on the clutch plate to engage that second or intermediate gear. There is an o-ring seal on the barrel of the cap that goes into the transmission and a gasket where the machined surfaces meet so there should not have been a leak here. There are 140,000 miles on this tranny.

I pealed back the heat shield to get the three small retaining screws (8 mm) out and removed the cap, then the servo assembly of a small piston and springs and about a six inch long shaft that easily pulls out of the transmission. I used the handle of a medium sized screwdriver between the car frame and the top of this cap to hold it in place while removing these screws and also while reinstalling them. There are springs pushing this cap out of the transmission about a half inch or so as you loosen the screws but nothing lethal. You can also just use your hand to hold it in place as you remove the screws.

Remember, I said that I pealed back the heat shield. That was the problem. It is a heat shield not an insulator. That heat shield was molded around this servo cap and transmitted the heat directly into that cap instead of into air flowing around it. It had cooked the o-rings and they were no longer soft and pliable and both were leaking pressure by and causing the grabby shift and external leak. The heat source is the exhaust pipe and catalytic converter that rests just beside the right side of the transmission.

The o-ring seal for the piston (servo), the o-ring seal for the cap and the gasket for the cap were 11 bucks and change at the Ford Parts place. I took the old ones off and replaced them using fresh Mercron V fluid to lubricate the parts and reinstalled. The whole thing takes maybe 30 minutes. You loose about a cup of fluid when the cap is lifted off of it's seal and you need not change the transmission fluid to do this.

When I finished this job, I made sure that I could get my fingers between that heat shield and all parts of the transmission. The heat shield will stop the heat but you need good air flow around it to get rid of the heat before it gets to your transmission.

The springs will cause the cap to come out some as you loosen the retaining screws but nothing menacing with this low to intermediate servo cap. DO NOT ASSUMN that the other similar looking caps on this transmission will act the same. I understand that some of them have large springs inside that can cause some serious pain and bodily harm if you open them up and let them loose without precaution.

These transmissions are not tolerant of any kind of foreign material or dirt being introduced into them. Make sure that the parts are very clean before you reinstall them and that no foreign material falls into the transmission while you have the cap removed. I personally clean everything until I can eat off of it before I lube it and put it back on or into the transmission.

If you elect to change these seals in your transmission, I hope your experience will be as pleasant as mine.

Regards,

Jim

phil-l
01-08-2006, 10:41 PM
Thanks for the info. I'll be using the pump-out method to partially change the transmission fluid in my 2000 Windstar in the next few days (prep before a trip), so I'll use this opportunity to take a closer look at the heat shield.

phil-l
01-10-2006, 10:27 AM
I looked at the heat shield on my 2000 LX 3.8 last night. Yes, it's very closely molded around the transmission, with little air gap. I tried to pry up a few of the edges, to make sure air can flow, but I probably need to completely remove the shield to do a better job of this.

The bolts attaching the shield keep it very close to the transmission - maybe I should try some shims under the bolts to hold the shield away from the transmission.

12Ounce
01-10-2006, 11:34 AM
Good info! Thanks!

joeuser742
02-08-2006, 11:26 AM
Wow, thanks for the posting. I am having the same problem and took a look under the van yesterday and sure enough that's where the leak was coming from. Now I have to goto the dealer and show them the parts that I need, they didn't know what it was.

Goag
04-06-2006, 02:18 PM
Hi,

I have a 99 Windstar with 3.8 L engine in it and it is doing the same thing. I would like to try this repair. I have been under the car and I have a Haynes manual that shows the heat shield but I can't locate it. Does anyone have some more detailed descriptions or photos I can look at?

The car has about 115k miles on it. This is the second tranny and I am trying to make it last. The first tranny went out at 60 k miles and it was a catastrophic planetary gear failure. No warning. I already have a drain plug and change the fluid often.

Thanks,

Mike

12Ounce
04-07-2006, 07:15 PM
NOTE!!! SOMETHING ELSE TO CHECK!

I am very thankful for this string. I was working 200 miles from home, pulling a trailer, when I started having the symptoms.. rather severely. I called my neighborhood tranny shop ... and was told I'd likely not make it home.

I ditched the trailer and carefully drove back home ... trying to avoid any unnessary stops.

I remembered/looked-up this string and others concerning the "low to intermediate servo". I gathered the seals and gasket and began work. That's when I had a real stroke of luck.

I was using a metal pan to catch the expected pint of fluid as the servo was removed. I heard a faint "clink" in the pan. I notice what looked like a small piece of circlip. A finger inside the tranny case found the rest of the circlip ... it was broken into three pieces.

I took a closer look a the piston assembly ... one circlip was still in place, but a groove in the piston rod showed the location of the second broken/missing circlip. I would have never realized there was a missing part had that small piece not fallen in the pan.

Anyway, there's probably not a chance in a million that you will have circlip issues on your servo. But just in case you do, ....you might want to buy a couple of #N804195-S2 ("rings" Ford calls 'em) as you pick up your other parts.

My repair, complete with new seals and gasket, seems to be OK. Thanks to "OldFaithful" and others who have contributed so much info on this subject ... probably saved me $1500 - $2000.

phil-l
04-08-2006, 09:35 AM
12Ounce -

Thanks for the info and congrats on noticing that crucial detail that made the repair work out.

Did you take any pics of the repair or the parts? Just curious - I haven't had these problems - but I tow with my Windstar (utility trailer and a popup camper), so I know the transmission is the weak point, and want to learn everything I can.

Thanks!

12Ounce
04-08-2006, 11:14 AM
I did not take photos. But the parts counterperson at Ford can make you a copy of the exploded view of the tranny showing both servos and all accumulator pistons ... complete with all the part nos.

As is often the case, these exploded view parts illustrations show how things go together better than Ford shop manuals or Haynes.

Stites
04-19-2006, 04:28 PM
New to here, all.

Good write-up on the servos. Would this apply to a '96 model trans???

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