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ATX Fluid Change

updated 3/21/02, updated 3/15/03 updated 9/30/2003,4/29/2004

Thanks to Don Rimdzius (via Jim Heaton) for this ATX Fluid change procedure:

The '96 Ford service manual recommends the following procedure to change the transmission fluid.  This will get out almost all the old fluid including the torque converter in one shot:

1) disconnect the lower transaxle fluid cooler line.
2) start engine, keep at idle, and fluid will drain from the open cooler line.
3) stop engine immediately when steady stream stops flowing (2 to 3 quarts will drain)
4) With engine stopped, add 10 quarts of new fluid to transmission.  Don't worry, it won't overflow or damage anything.
5) start engine again and fluid will again drain from open cooler line.
6) stop engine when steady stream stops flowing (10 quarts will drain)
7) reconnect trans cooler line.
8) add 2 quarts of new fluid to transmission
9) check fluid level under normal operating temp and add in 1/2 pint increments until full.

Apparently, the oil is some what stratified as it drains removing old oil first.  I've used this procedure on all 3 of my Fords ( '89 Taurus with AXOD, 95 Windstar with AX4S) with excellent results.  I only use Mobil synthetic trans fluid and feel the superior temp rating is great insurance against premature trans failure.  My '89 has Ford's engine mount wrenching 3.8L with 230 ft. lbs. torque and My Windstar pulls a trailer.  The Synthetic fluid will cost about $75 for this change.

On the 96+ SHO, the transmission fluid cooler lines enter the transmission at the front left side of the car.  This should be directly underneath the battery location.  You reach the lines from below the car.  There are two lines which enter the transmission, one a few inches directly above the other.  The fluid leaves the transmission in the top one and returns in the bottom one.  Removing the bottom one allows you to direct the fluid exiting the disconnected hose into a pan.  You can attach an extension hose but I didn't need to.  It helps if your wife starts and stops the car while you direct and watch the fluid flow.  Very little fluid will drain until the car is started.  None should drain out of the opened fitting on the transmission.

The following commentary was offered by Mike Collins:

The first thing I did was drop the transaxle pan to change the filter ($18, local FORD dealer had them in stock.)  If you have never done this before its really easy!  Loosen every other screw first.  Then go back for the others.  Loosen them to the point at which you can turn them by hand.  Now, gently pry the passenger side end of the pan SLIGHTLY open with a screwdriver to start the fluid draining.  As it slows, loosen the screws as needed to get as much fluid out before actually dropping the pan.  Take a good look at the new filter.  Do NOT panic if you remove the old filter and the pink, rubber gasket doesn't come off.  I had to do a little prying and pulling with a small screwdriver and a pair of needle nose pliers to get it out.  Once you have this taken care of, (if it happens to you too), you can now install the new filter.  While the pan is off, make sure you clean the "donut" shaped magnet than is stuck to the inside, bottom of the ATX pan.

FORD told me this gasket on the AX4N is reusable, so go ahead and re-attach the pan.  The screws should be tightened to 79ft-lbs as per the Helms Manual.

Pour 3 quarts back into the ATX. (Use the cheap stuff since this will get drained later)

The transaxle fluid cooler line to disconnect is NOT exactly under the battery.  It is on the same side of the car though.  The black, plastic cover that attaches to the front bumper/air damn to cover the bottom side of the radiator must be removed to access the lines.  Also, it will help to remove the plastic splashguard inside the wheel well.  While under the car, you will see (starting at the engine) the radiator, then a smaller radiator, and then there is the smallest one up front.  It has two lines going into it on the "battery end".  The TOP one is the one to pull when you are ready to drain the remainder of the fluid.  You WILL need someone to help you out with this.  One person to turn the car off the second the fluid stops flowing and the other to watch the fluid and hold onto the hose.  Now you are ready to pull the ATX cooler line and follow the directions from the 96-99 FAQ.

Concerning step number 8, I found that 2 quarts is definitely not enough.  I had to put in 3 to 4 quarts, but this will vary according to how much you drain during the rest of the process.  Keep checking the dipstick and when you think its close, take the car out for a short drive in the neighborhood and be gentle.  I could tell right away that there wasn’t enough fluid simply from the way it shifted.

I used AMSOIL Synthetic ATF for this flush & fill.  It took me 14 quarts to finish the job.  I used the regular, cheap ($1.07/quart) MERCRON type ATF to refill the ATX after the pan removal.  This was the first time I had ever done ANY work on an ATX so needless to say this is a simple job that anyone with a few tools, a floor jack, and jack stands could do. 


The tranny fluid / filter change procedure on V8SHO.com is almost 100%accurate with the exception of one minor detail. After disconnecting the hose from the upper cooler on the drivers side be sure to add 2 feet of hose to the cooler fitting and have this empty in to a bucket. The fluid will NOT empty from the disconnected cooler line. If you do not do this you will end up with tranny fluid seeping out from the seam of the lower valance.  

Chris A.99 SF

One thing to add to the tranny fluid change part is that on the 99's, at least mine, is that the fluid actually comes out of the cooler tube. If you disconnect the hose on the drivers side from the tranny cooler you NEED to attach a hose to the barb and empty that into a bucket, or else you will have a LARGE mess on your hands.

Chris A.
99 SF

I have a couple of comments to add to the ATX fluid change. 1) The torque given in the article is 79 ft-lbs. It seemed too high for 8mm bolts and my Haynes manual said 108 inch-pounds. This would be near 9 foot-pounds. It is more reasonable for a sheet metal pan and small screws. 2) The hose needed is 3/8 ID.

Jay Kellogg

Just thought I'd again thank everyone. I completed the transmission fluid change with Mobile1 synthetic. The instructions on the V8 SHO site were very helpful.

My comments to the change are as follows. 
I have a 99 and I used a 7/32" socket and extension to loosen the upper clamp on the ATX cooler in front of the radiator. I also used a 5 gallon bucket to catch all the fluid. You will need to place a 3/8 OD (tubing of your choice) to the top "barb" of the cooler to allow you a nice clean change. Make sure it is long enough to go directly into the bucket but not too long because there will be a lot of fluid emptying into the bucket and you need to watch the flow of the fluid as it comes out of the tubing. I needed exactly 13.5 quarts to refill it to the appropriate level but I think this will depend on how quick or how fast you shut off the engine when the steady stream of ATX fluid diminishes. Good luck to all those do it "yourselver's" like me and if I can help anyone please feel free to ask and I will reciprocate as all before me have so generously helped me.

Tim Dove
99SHO welded 

I needed more like 17-18 quarts to flush the whole system (converter last), I don't know how Tim Dove only needed 14. I used a shop with a lift in good light and dumped Mobil 1 ATX until the new fluid ran out with out streaks of the old. 4 quarts either way is not trivial when it cost $5/qt. for Mobil 1 ATF.

One other caveat, 18 quarts of Mobil1 ATF was all I could find in the greater metropolitan area of Decatur IL. The stuff does not grow on trees in some areas. - Buford

Flushed my tranny a couple of weeks back. Followed the instructions on the site. Have a few comments.

  1. Working laying on your back in your driveway out of a small toolbox is a lot different than a shop with six lifts and several roll-a-ways. I got spoiled. 
  2. All kinds of stuff ends up under that front valance. You’ll be surprised when you open it up. 
  3. The transmission cooler on this car is surprisingly small. Mine was also bent up pretty good from stuff hitting it. I took the time with some needle nose pliers to splay the fins back open. I’m pretty sure I increased the actual effectiveness by doing this. It had probably been degraded somewhat. 
  4. Make sure you get a wide catch bin if you are going to pull the pan. I used a 5 gallon bucket and had a nice mess on my hands. I do recommend pulling the pan. My magnet was coated. When putting the pan back primed with ATF fluid use your floor jack to lift and hold it into place. Otherwise you will have a lake of ATF fluid in your driveway. 
  5. The gasket on the filter is not a typical gasket like one might expect on say a valve cover. It is a metal ring with gasket material on either side. I spent a lot of time carving out the material, and all I had to do was pull the whole thing.
  6.  3/8” OD hose might work, but 3/8” OD poly tubing was a no go. Had to split the tube to get it over the barb and ended up with another nice mess on my hands. 
  7. All in all I think I went through 17-18 quarts of ATF fluid. Added a bottle of the Lucas product as well. Happy with the results.


Yep, the gasket is a reusable one with metal donuts where the bolt goes through it a replacement is 22 bucks. - Christian A


A little background, this is if you are going to drop the pan and change the filter and clean up the magnet etc. This saves the drippy mess one normally ensues when removing the pan and letting it drain. About 2.5 gallons will drain so have a big drain pain to siphon to.

I found it much simpler to stuff some 1/4" ID Vinyl tubing down the fill/dipstick tube, and set a bucket on the floor (jack the car some to elevate the ATX) and siphon the pan empty. Then pull the bolts and drop the pan practically drip free. Standard physics laws apply that the down stream end of the tube must be lower than the bottom of the ATX pan. Took about 20 minutes but the pan was 90% empty when I dropped it.

Scott Krietemeyer


The top unfinned tube in front of the a/c condenser, at the bottom. undo the line at the driver side of the tube and place a long hose there.
Buy a short piece of metal tubing. Get the ends flared a bit. Use this to join the piece of hose to the hose you just connected. Place the hose from the cooler in an empty bucket.
Place the other hose in a large container of fresh ATX fluid. Have someone else start the car and watch the fresh fluid it should drop.
Have the car shut off and swap to another container of fresh fluid. If you can buy the large pails that Farm supply of bulk oil/lube suppliers sell. {same fluid as P/S}
Do this until the fluid coming out of the cooler is clean.
Also have the person in the car cycle the transmission selector with the parking brake on, the service brakes and the car at an idle. This will circulate fluid through the valve body and channel plate.

Did I forget anything...???


Yes, how to use the shift key!!!



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