Hello people!
Well I just wrote my second guide to give back to the automotive forums and it's users a little of the help I've received. This time I will show how to replace the VSS on 1999 and later windstars with AX4S transmissions.
Although I'm not pretty sure it should apply to AX4N transmission too, the only difference is the orientation of the sensor; in AX4S transmission it is vertically oriented while in the AX4N it is horizontally. Maybe some other user can comment about it.
You won't need any special tools and won't have to deal with rusty exhaust bolts, motor mounts, etc. It's pretty straight forward.
You can get ahead of time and buy/order the VSS compatible with '99 and above windstars.
NOTE: You can click on each image for a larger resolution version of it. The last two links will take you to a couple of videos showing the sensor.
Remove the negative battery terminal before you attemp anything else.
First of all you need to remove the wiper blade arms using a 15mm socket. It's easier to remove them when the hood is still in the closed position.
Second you need to remove the wiper cowl, it takes 4 plastic phillips head screws with their respective holding clips at the bottom and once you've done that, you need to carefully pry the four plastic clips that hold the upper part of it, make your way from the upper corners to the center of the cowl, do this carefully because those tabs can break very easily. Take your time! Once it's loose you'll need to alternate between opening and closing the hood to get it out through the backside towards the windshield.
Then you'll need to remove the other part where the wiper motor and the mechanism that moves the blades. It will take about 12 bolts to get it out.
Once you've finally removed both parts, you can remove the smaller blower duct near the center of the engine compartment and you will see something like this:
And this is where the blower duct is attached to:
The next part is to disconnect the VSS harness, you can locate it by looking form the drivers side straight under the coil pack, you can see it in the picture (near the center of it) below the blue and white dots:
In the next picture you will see the spot where you'll need to use to get to the VSS (from this place it is located right between the rear exhaust manifold and the engine block). Route your hand through the square you can see at the center of the image, right between the rubber hoses and the plastic wiring tubing. You can choose to remove the vacuum hoses for the brake booster and the EVAP Regulator from the intake manifold to have some more free space:
Now that you know the route and have enough space, you can take your hand under there, access through the driver's side of the exhaust manifold (don't try to use the other openings as your hand won't fit), and feel the rectangular heat shield on top of the VSS, in the next picture you can see it at the upper left (it's not a very good picture but I posted it just to give you an idea):
This video will show you (kind of) the route your hand needs to follow to get there. In it you will see the VSS and the heat shield for the first time:
http://youtu.be/JTmgpmvDNJM
TIP: It is easier to reach the VSS when you're sitting on the metallic part on top of the radiator and the battery. It doesn't matters how tall you are (I'm 6'2") it's still hard to reach there.
Use an 8mm socket to remove the bolt (located at the opposite side of the wiring) that holds both the shield and VSS in place. The best way to do it is using a ratchet, a long extension and universal joint. Insert it thorugh one of the openings in the exhaust manifold and use your hand to put the socket on the bolt. It depends on each person but I found it easier to use the ratchet on ly to loosen the bolt and then getting it out by hand.
Make sure you don't loose it!.
Use a rag or compressed air to blow as much as you can around the VSS to get rid of as much dust as you can. You can finally take the VSS out, it is coated with some transmission fluid so it might be slippery. If you don't have the replacement already make sure you cover the hole with a rag to prevent any dust from entering the transmission.
In the next video you'll see the VSS with the shield removed and ready to be taken out.
http://youtu.be/CIndRLvp97w
Install new VSS and tighten the bolt to 89 lb-in, 7 lb-ft or 10 Nm; any measuring units you want to use.
So that's pretty much it. Assembly is the reverse of the removal procedure, make sure you put everything back together the right way, tighten those bolts, reconnect the battery terminal and GET THAT THING TO BURN SOME FUEL!
Any doubts, comments, etc. feel free to post them here or send me a private message.
Greetings from Mexico!
Oscar.