Calling All Ax4n Transmission Mechanics!!!!

[50mustangs]

hey guys, I have a 2003 Windstar LX with 60,000 miles. It has an AX4N transmission. the van drove through a red light and once it got to about 50 MPH it was like you kicked it into neutral and has been like that since. It shifts in and out of park and I checked the linkage to make sure it was properly working and it does. When you shift into gear the idle doesn't change at all. You can rev it up in any gear (reverse, drive, 1st, 2nd) and the van won't hint to moving even a little bit. the fluid was checked on site while it was warm and the level and smell was perfect. no burnt smell at all and very clean. had it towed to AAMCO and they said the transmission is toast and for $3,000 they would repair it. When asked what the problem was they wouldn't give any detail but would just say it needed rebuilt or replaced. I think it maybe something less than that so I'm going to tackle it myself. I've rebuilt an AOD in my 85 Mustang GT and I've built an 85 F-150 4x4 from the ground up among numerous other projects so I know a little about the mechanics of how things work but I have no experiance with the newer electroniclly controlled transmissions. Any tests to diagnose the problem would help me greatly. I can't afford a Rotunda transmission tester at about $1,000 so unless someone knows where I can borrow one or something equvalant to that then it's out of the question. I could easily just replace it with a remanufactured for about $1200 but I just want to be sure it's not a sensor or something small. Thanks alot guys. I'll be looking forward to any suggestions. P.S. would an OBDII help at all with pulling any codes from the transmission?

[50mustangs]

anybody? please help!!!!

[jonmark1985]

I'm not much help, but call your local Ford garage and see if they have the machine to check it out.

[50mustangs]

I have some new info. I borrowed a snap on tool and pulled the codes here's what I've got. first code PO713 trans fluid sensor high Input. second code PO750 shift solenoid A fault. third code PO753 shift solenoid A electrical. fourth code PO760 solenoid C fault. And fifth code PO763 shift solenoid C electrical. I did various other tests with this machine and found that the TR sensor was working properly. the transmission temperature in voltage was high @2.67 volts and at 195 degrees Fahrenheit it should be .60 volts. looks like it maybe more burnt than I suspected. I've noted all perameters so if anybody can help and need a certain perameter please ask and I'll give it to you.

[50mustangs]

can anybody help? somebody has to have some idea.

[mpeoples]

Hi. I'm a DIYer (no expert), but I did rebuild my own AX4N transmission, so I've seen the guts of the thing. There's a couple of things to check:
- Is the fluid burned? If it dark or black, or has black specks in it, you probably chewed up a clutch pack. You can usually check it by taking the transmission fluid dipstick out, and dripping fluid on a white piece of paper. The better way is to drop the transmission pan and have a look, but it's messy.
- The other thing you need to look for in the fluid is any metallic particles. You might see these by dripping fluid on the paper, but you might not see any. That's because there's a magnet in the pan that's suppose to keep them from flowing back into the transmission. If you drop the pan, you would see them if they exist. You would also see them in the filter.

That said, there's a problem with some older (mine was a 1996 Windstar AX4S) where the wave spring in the direct clutch (I can't remember which, but it doesn't matter), breaks, which causes the clutch pack to partially engage, and this eventually causes it to wear out. If you see a lot black specks, that's where they are most likely coming from.

I'm currently rebuilding an 1997 AX4N with a friend, and the problem with it was a valve in the valve body that jammed because of a broken retain clip. Sonnax has a technical note on this, and it is a known problem. To fix it, you have to buy the kit and the reaming tool, which will cost you about $100.00 or so. If this valve jams, a clutch pack gets shredded.

If you see metal in the fluid, then a sprag or bearing might have gone bad.

That all said, my experience with the Windstar was tough (you know when you only only do things once, you make all the mistakes). However, there's no reason why you can't rebuild it yourself for $200 - $300, assuming there are no major hard parts damaged.
The difficulty with the Windstar is the fact that you have remove the engine support to get it out. This requires a hoist, and something to hold the engine up after the support is removed. Ford, of course, has a special set of brackets for this, but I made my own out of uni-strut, threaded rod, some bolts, and chain.

You will need to get an ATSG manual (or better still, the factory service manual, which I have for my Windstar). You might also use a Haynes guide, as they will usually tell you how to get the transmission out. The pictures should make it clear what you have to do to support the engine. I suppose you could just leave it on the hoist, but you're going to have to figure a way to support the engine if you're going to work under it safely.

You'll also need a transmission lift or a floor jack with something to support the transmission. I suppose you and a friend could guide it down, but dropping it would be bad. You'll also need help getting the support member down as it's heavy.

What I've just describe will be pretty obvious to you, so you're not going to need any special tools or anything, just yet.

Now, if you decide to directly inspect the shift solenoids, it can be done with the transmission still in the vehicle, it's just not easy. I don't know what the differences are between a 1996 and a 2003, but I could get the cover off of the front of the transmission while it was still in the vehical. You have to support the transmission and engine, remove all the the "stuff" that's in front to the cover, then remove the front transmission support bracket that surrounds the cover. At that point, you can work the cover off. It also helps if you lift the end of the engine with the cover up a few inches (which may require loosening some mounting bolts). This give a bit of extra clearance.

You can check the solenoid's resistance using a mult-meter, but you could also do that without remove the cover, by checking the electrical connector on top of the transmission. You'll need a manual with the pinouts, but that's as good a way as any, and should probably be done first before you remove anything. The resistance values will be in the ATSG manual (which you can get from any transmission supply place).

If you find a bad solenoid, replacing them is pretty easy, and they're not very expensive.

If you do have to remove the transmission, the rebuild will be described in the ATSG manual. You've done stuff like this before, so you shouldn't have any problems with this.

The reason it costs so much to have AAMCO do it, is it's so time consuming to get the transmission out and in. So, work carefully. My mistakes required me to remove it two additional times (although I got pretty good at).

You should allow a couple of weekends for this, and having a friend around (who at least can hand you tools) really helps. The rebuild itself isn't rocket science, so your past experience indicates you shouldn't have any problems with it.

Remember to check the resistance on those solenoids!

This might have been a bit rambling, but that's just me. Let me know if you need more help.

[50mustangs]

mpeoples, thanks for your reply I was starting to lose hope. that is exactly the kind of info I was looking for. I'm going to go ahead and get the manual you mentioned. I'm also going to check the fluids using your method with the paper. that is a really good idea. the visual check I've already done doesn't show any signs of being burnt it looked really good but using the paper I may see something I over looked before. I'm really intrested in checking the solenoids using the plug on top the transmission with a multimeter. where can I get more info on this? as far as what plugs to use and what wires to check for resistance, continuity or what values I should be getting. thanks. I'll be looking forward to any info provided.

Originally Posted by mpeoples

Hi. I'm a DIYer (no expert), but I did rebuild my own AX4N transmission, so I've seen the guts of the thing. There's a couple of things to check:
- Is the fluid burned? If it dark or black, or has black specks in it, you probably chewed up a clutch pack. You can usually check it by taking the transmission fluid dipstick out, and dripping fluid on a white piece of paper. The better way is to drop the transmission pan and have a look, but it's messy.
- The other thing you need to look for in the fluid is any metallic particles. You might see these by dripping fluid on the paper, but you might not see any. That's because there's a magnet in the pan that's suppose to keep them from flowing back into the transmission. If you drop the pan, you would see them if they exist. You would also see them in the filter.

That said, there's a problem with some older (mine was a 1996 Windstar AX4S) where the wave spring in the direct clutch (I can't remember which, but it doesn't matter), breaks, which causes the clutch pack to partially engage, and this eventually causes it to wear out. If you see a lot black specks, that's where they are most likely coming from.

I'm currently rebuilding an 1997 AX4N with a friend, and the problem with it was a valve in the valve body that jammed because of a broken retain clip. Sonnax has a technical note on this, and it is a known problem. To fix it, you have to buy the kit and the reaming tool, which will cost you about $100.00 or so. If this valve jams, a clutch pack gets shredded.

If you see metal in the fluid, then a sprag or bearing might have gone bad.

That all said, my experience with the Windstar was tough (you know when you only only do things once, you make all the mistakes). However, there's no reason why you can't rebuild it yourself for $200 - $300, assuming there are no major hard parts damaged.
The difficulty with the Windstar is the fact that you have remove the engine support to get it out. This requires a hoist, and something to hold the engine up after the support is removed. Ford, of course, has a special set of brackets for this, but I made my own out of uni-strut, threaded rod, some bolts, and chain.

You will need to get an ATSG manual (or better still, the factory service manual, which I have for my Windstar). You might also use a Haynes guide, as they will usually tell you how to get the transmission out. The pictures should make it clear what you have to do to support the engine. I suppose you could just leave it on the hoist, but you're going to have to figure a way to support the engine if you're going to work under it safely.

You'll also need a transmission lift or a floor jack with something to support the transmission. I suppose you and a friend could guide it down, but dropping it would be bad. You'll also need help getting the support member down as it's heavy.

What I've just describe will be pretty obvious to you, so you're not going to need any special tools or anything, just yet.

Now, if you decide to directly inspect the shift solenoids, it can be done with the transmission still in the vehicle, it's just not easy. I don't know what the differences are between a 1996 and a 2003, but I could get the cover off of the front of the transmission while it was still in the vehical. You have to support the transmission and engine, remove all the the "stuff" that's in front to the cover, then remove the front transmission support bracket that surrounds the cover. At that point, you can work the cover off. It also helps if you lift the end of the engine with the cover up a few inches (which may require loosening some mounting bolts). This give a bit of extra clearance.

You can check the solenoid's resistance using a mult-meter, but you could also do that without remove the cover, by checking the electrical connector on top of the transmission. You'll need a manual with the pinouts, but that's as good a way as any, and should probably be done first before you remove anything. The resistance values will be in the ATSG manual (which you can get from any transmission supply place).

If you find a bad solenoid, replacing them is pretty easy, and they're not very expensive.

If you do have to remove the transmission, the rebuild will be described in the ATSG manual. You've done stuff like this before, so you shouldn't have any problems with this.

The reason it costs so much to have AAMCO do it, is it's so time consuming to get the transmission out and in. So, work carefully. My mistakes required me to remove it two additional times (although I got pretty good at).

You should allow a couple of weekends for this, and having a friend around (who at least can hand you tools) really helps. The rebuild itself isn't rocket science, so your past experience indicates you shouldn't have any problems with it.

Remember to check the resistance on those solenoids!

This might have been a bit rambling, but that's just me. Let me know if you need more help.

[mpeoples]

Sorry for the delay, seriously busy at work.

That manual I mentioned will have the pinouts. I only have references for the AXODE & AX4S, but because the valve body of the AX4N is so similar and the connector appears to be identical, it's probably a safe bet that the pinouts are the same.

Well, I drew you a picture before I realized that I can't put it in the reply. So here are the PINOUTS of the connector on top of the AX4N case (wire color in parentheses):

1 - EPC Ground (Blue)
2 - EPC/MCCC Power (Green)
3 - SS3 Ground (Yellow)
4 - MCCC (TCC) Ground (Brown)
5 - SS1, SS2 , SS3 Power (Red)
6 - SS1 Ground (Orange)
7 - TOT- (Black)
8 - SS2 Ground (Pink)
9 - TOT+ (White)

First, these colors and pinouts may not match your transmission. Over time, the wire colors fade significantly, so you really need to look at a connector diagram. I'll describe the connector as you would see it if you were looking straight down at it from above.

The connector's "top" two corners are "chamfered" and the "bottom" of the connector has a row of three pins. The bottom, "left" side has only one pin. There are three "rows" of pins and/or four "columns" of pins. So if you are correctly oriented, then think of this like a grid with row 1 at the top of the connector, row 2 below that, and row 3 at the bottom. Column 1 is on the left side (and has only one pin), column 2 is to the right of that, column 3 to the right of that, and column 4 on the right side of the connectors.

So, using this "grid" the pins are as follows:

Pin 1 - Row 1, Column 2
Pin 2 - Row 2, Column 2
Pin 3 - Row 2, Column 1
Pin 4 - Row 3, Column 2
Pin 5 - Row 3, Column 3
Pin 6 - Row 3, Column 4
Pin 7 - Row 2, Column 4
Pin 8 - Row 2, Column 3
Pin 9 - Row 1, Column 3

Testing the five solenoids in the case consists (potentially) of three tests. One is a resistance test (which is what you're going to perform), the second is a ground check, and the third is a function test (which you have to be careful with). The resistance test consists of testing the resistance (ohms) through the solenoid. To do this, you set the multimeter to a low range (something that will read in the 5 - 100 ohms range. Put the negative lead on the power pin of the solenoid you want to test (for the shift solenoids, that's pin 5) and the positive lead on the ground of the solenoid you are testing. The reading you get is the resistance of that solenoid.

One note, because the connector space is small, you may need to use a small clip or other fixture to hold the negative lead on the power pin. It makes it easier to do the test. Here are the values you should be getting for the five solenoids:

Shift Solenoids (SS1, SS2, SS3) = 12 - 25 ohms
EPC Solenoid = 3.2 - 5.5 ohms
MCCC (TCC) Solenoid = 0.98 - 1.6 ohms

To check the ground (for shorts), touch the positive lead of the multimeter to the case or engine, and the negative to the power pin of the solenoid you're testing.

To perform a functional test, you need a 12V DC source, like the battery. It is critical that you not get polarity reversed, or you can ruin the diode in the solenoid, then you will have to replace it. Connect the +12 DC voltage source to the POWER pin of the solenoid you are testing. Then, preferably using a mechanic's stethescope placed on the outside cover of the valve body, momentarily connect the ground pin of the solenloid you are testing to a chassis ground. Listen for a click. That is the solenoid actuating.

That all said, getting a manual is the best way to have all of this information. What I said above may not apply in your case, so you're on your own in that respect. The manual will have the correct pinouts and values for your transmission.

[mpeoples]

I'm still looking to identify those accumulator springs, but I found the following catalog for valve bodies that will have a good picture of the AX4N.

http://www.centralvalvebodies.com/CV...EMBER_2006.pdf

[50mustangs]

wow mpeoples, I'm very impressed with this information you've provided. I'm going to give this a shot. Looks like it will be Thursday before I get a chance. I'll let you know what I've found out. thanks again.