Transmission Speed Sensor Discrepency

[J-Willie]

Greetings all,

Been searching every resource I can but I cannot find an answer to my problem!

1998 3.0L Windstar 142,XXX miles, production date of 4/97

Replaced the transmission ourselves with a reman unit and after a lot of cursing and rusty parts breaking, etc, everything was back in place except for one problem. The speed sensor is a different type.

The old transmission had the typical speed sensor gear/shaft that is driven off of the final drive unit, big bulky sensor which I assume to have an analog output.

The new transmission has the output shaft sensor, sort of in the middle of the case, and I also assume a digital signal.

The new transmission has a block-off plate installed where the older style sensor should be installed. Well the crappy part is the plastic helical gear on the final drive unit isn’t installed so I can’t even install the old sensor on the new trans.

Clearly this should have been caught before the transmission was installed but the lack of missing a family vehicle and how crappy the job was, well we messed up. So we called the company and were told that as of recently they are now putting both sensors on the transmissions to avoid this exact problem and our only option was have the old one sent back, install the plastic gear for the old sensor, and re-install it. The thought of having to do the job again is aggravating and I really can’t justify the labor expense of a shop R&R’ing the trans.

First thing I did was hook the new sensor up to the car, just to see what happens. Well going about 15 miles down the road reads out to about 140 on the speedo, no dice because the transmission freaks out thinking we just accelerated from 0-60 in .2 seconds.

So after seeing the the sensor was sending far more information that it needed to I tried a variable resistor in line with the sensor to the ECM which helped a ton but the speedo still doesn’t work right. With the right amount of resistance the transmission shifts up perfectly but doesn’t have good downshift quality since it still doesn’t know how fast it is going.

Now if you haven’t figured it out I am trying everything I can think of to avoid having to replace the transmission, again. I then tried to figure out when ford did the sensor switch from the VSS to the OSS but couldn’t find a clear cut answer. The best I could do was 98-99 was when they switched over. Maybe mine being an early production is why I had the VSS.

I was able to attain an ECM from a 99 3.0 Windstar for very cheap and was hoping there were VERY few changes if any (the speed sensor being one of them) that happened over the year. I couldn’t find any documentation as to what may have changed or even anything about this speed sensor nonsense! Well the ECM failed to start the vehicle. A 99 3.0L Windstar ECM failed to start a 98 3.0L Windstar. What the heck?

So I need help from those who know this vehicle, or ford for that matter, my expertise lies in imports so I am totally lost.

To sum things up again;

1)Speed sensor difference, VSS to OSS, when?

2)Changes between years, specifically 98-99-00, for instance ignition tables, anything that wouldn’t allow it to start

3)I can’t be the first one to ever come across this discrepancy!! Is there any way to solve this without replacing the transmission or is there anyone I can talk to? I’ve avoided the Ford dealers with this one for obvious reasons.

Help?

[wiswind]

I would go to a FORD dealership parts department.
Have your VIN, and they should be able to help you.
Mid-year changes can bite you, and the VIN should cover that on their computer.
They have a really good parts look-up system on their computers.
They have pictorial break downs that get right down to the part(s) involved.
I have not seen anything that comes close to the detail that they have.
Paying list price for the speed sensor will be cheaper than trying to battle with it on your own.
It sounds like you have reached over $100 of frustration factor already (I do put a price on that).

I remember a post on a FORD forum where a FORD technician recommended replacing the speed sensor with a genuine Motorcraft sensor because the Motorcraft sensor came with a new gear.
Make sure that you get the gear and sensor when you buy one.

I am only familiar with the '96, and it has BOTH the Vehicle Speed Sensor (VSS) that is located on the back side of the transaxle......at mid point.
It is hard to get at to change due to all the things that are in the way.
Otherwise, it would be simple to change.
I think that Alldatadiy has it listed as OSS at some point also...as well as VSS.....but it would be the same measurement.
If they moved things around, the breakdown at the FORD dealership will show it for your vehicle.

The other sensor is the Turbine Speed Sensor (TSS), which is located on the driver's side end of the transaxle.
This sensor measures the speed of the shaft that comes out of the torque converter, but before the gear ratios of the 4 speeds.
The PCM knows the speed into the torque conveter from the engine RPMs, and the TSS tells the PCM how much slip there is in the torque conveter.
This is a value that helps the PCM control the transmission, but not useful in determination of the vehicle speed.

But then, asking you to return the transmission so that they can install the sensor?......who is paying the shipping charges?
One would think that they could put the sensor in a little box and send it to you......FEDEX overnight would be a small fraction of the cost.

[J-Willie]

That is one of the problems. The standard VSS everyone knows on here is a magnetic sensor driven off of a gear, then goes 90 degrees into the case which is then driven off of another gear.

For this sensor to work there has to be the big round gear inside of the transmission case to spin the vss. The new transmission does not have it installed so using the old VSS is out of the option.

So this isn't a how to replace the sensor and with what part number. It's how can I trick my car into thinking I have the other sensor, if it's even possible, by altering the signal sent or altering the computer for signal received. Otherwise the transmission will have to come out again! And they would pay shipping, they offered. But who's paying labor to have it come out!? I'm expensive!

The last few times I've been at the Ford dealership there have only been crotchity old men working that don't want to be there and have a very, very tough time finding the parts I need, even with my Vin. It's frustrating, and this problem is even more frustrating, especially to explain to someone
who won't understand what I just said.

Thanks for the reply though Wiswind, I was kind of counting on one from ya.

[searcherrr]

Originally Posted by J-Willie

That is one of the problems. The standard VSS everyone knows on here is a magnetic sensor driven off of a gear, then goes 90 degrees into the case which is then driven off of another gear.

For this sensor to work there has to be the big round gear inside of the transmission case to spin the vss. The new transmission does not have it installed so using the old VSS is out of the option.

So this isn't a how to replace the sensor and with what part number. It's how can I trick my car into thinking I have the other sensor, if it's even possible, by altering the signal sent or altering the computer for signal received. Otherwise the transmission will have to come out again! And they would pay shipping, they offered. But who's paying labor to have it come out!? I'm expensive!

The last few times I've been at the Ford dealership there have only been crotchity old men working that don't want to be there and have a very, very tough time finding the parts I need, even with my Vin. It's frustrating, and this problem is even more frustrating, especially to explain to someone
who won't understand what I just said.

Thanks for the reply though Wiswind, I was kind of counting on one from ya.

In those situations I tell them that I'm good with computers and offer to find the part myself. You should try it sometimes, but you have to be careful as to not step on their toes .... too too much.

What about leaving the transmission in and swapping your instrument panel for a digital one? Would the tranny company pay for that rather than shipping a new tranny back? or would a lot more go into swapping to a digital instrument board than you'd want to deal with?

[12Ounce]

Originally Posted by J-Willie

..... at the Ford dealership there have only been crotchity old men working that don't want to be there and have a very, very tough time finding the parts I need, even with my Vin. It's frustrating.....

I feel your pain ... I think Ford part's counter people have helped so much to dig Ford's grave. It takes tremendous "people skills" to deal with some of the folks at the parts counter!

'99 was a big change year for the Winnie, but I never thought about this particular one. Too bad the tranny-folks you bought from were not on top of it.

It just so happens I'm soon to change out the tranny in my '99. I intend to buy the tranny thru Ford. I've already checked the price/availability. It's interesting that the parts guys (I luckily know a couple of good ones) told me I would have to provide the exact plate info off the old tranny before they could match me up with a working replacement as two trannies are available for the '99 3.8. So ... it must have been a mid-year upgrade.

[searcherrr]

Originally Posted by 12Ounce

I feel your pain ... I think Ford part's counter people have helped so much to dig Ford's grave. It takes tremendous "people skills" to deal with some of the folks at the parts counter!

'99 was a big change year for the Winnie, but I never thought about this particular one. Too bad the tranny-folks you bought from were not on top of it.

It just so happens I'm soon to change out the tranny in my '99. I intend to buy the tranny thru Ford. I've already checked the price/availability. It's interesting that the parts guys (I luckily know a couple of good ones) told me I would have to provide the exact plate info off the old tranny before they could match me up with a working replacement as two trannies are available for the '99 3.8. So ... it must have been a mid-year upgrade.

How many miles did you get out of that tranny 12Ounce? Not to hijack your thread, but the Ford trannies of this type are crap and under-built for what the 200HP Essex engine in your/our Windstars put out. You should look into having someone beef it up, give it better pumping ability and beefier shifting parts. I didn't know this was possible till recently, but Marshall Engines can bump you up to what they call Stage 1 giving you more torque and a longer living tranny and its only $300 more for the 1 I was quoted bringing it to $1800 total for 3 year 100,000 mile warranty. Do what you want, but I've researched these trannies to an INSANE degree in the past 2-3 weeks and the AX4S and even AX4N just isn't enough to last on these higher powered Essex engines we have.

[12Ounce]

Searcherr,
There's about 220k miles on the clock. And its still going ...but the torque converter clutch is beginning to slip. I did have to replace a broken pump shaft (and valve body) at 90k miles ... I always attributed this early failure to a worn-thru powertrain harness, which caused some violent jerking.

I appreciate the info. I would prefer to rebuild/reuse my basic tranny ... but that would add to the turn-around time. But I'll check it out. Thanks.

[searcherrr]

Originally Posted by 12Ounce

Searcherr,
There's about 220k miles on the clock. And its still going ...but the torque converter clutch is beginning to slip. I did have to replace a broken pump shaft (and valve body) at 90k miles ... I always attributed this early failure to a worn-thru powertrain harness, which caused some violent jerking.

I appreciate the info. I would prefer to rebuild/reuse my basic tranny ... but that would add to the turn-around time. But I'll check it out. Thanks.

WOW!!!! If I had that experience with one of these trannies I'd feel the same way you do. Thats the first time I've heard of one of our trannies lasting that long. WOW. Perhaps it lasting as long as it did though was due to your pump shaft and valve body replacement with a better one..... and perhaps you drive it "reaaaaaaaalllllly" soft.

[C. Cleve]

Hi, You have the WRONG transaxle,, Like some of the info given here, You need the EXACT tag info from your original trans, By the way, The trans shop you dealt with needs to get on the ball..Hope you get it solved...Good Luck,, Clay...(retired ford trans tech)

[wiswind]

When ordering parts, it is best to give them your VIN, as there have been some mid-year changes.
The online FORD dealership parts departments provide a place for you to enter your VIN, and state that they cannot be responsible if you don't give them your VIN, and get the wrong part.
I have had this happen 2 times....both for simple, inexpensive parts, 1 was the PCM temperature sensor, and another was a EGR vaccum solenoid, and my year/engine was not enough.
Was my own fault......and not worth bothering about.....but the extra step of getting the VIN would have avoided the issue.
There is NO telling what part may have had a slight change during a given model year.....does the same job....but does not fit.

I would expect a tranny company to request a VIN when you order, unless for CERTAIN there was no mid-year change.....which would suprise me.

When I ran into tranny issues, I bit the bullet and went through FORD for a re-manufactured unit.
It hurt, $2800+ in 2000 or 2001, but I did not want to go down the same road again in the future.
I am years....and almost 100K on the replacement unit....and it is doing really well, no shifting or slipping issue.
I changed from having a dealership change the fluid every 30K miles to doing it myself with synthetic once a year, and also installed a big auxillary cooler, and when in stop and go traffic, I have the A/C on....which keeps the radiator fans running........as I keep an eye on the temperature, which stays low and steady.....all of which contributes to a longer life for the tranny.

I really understand the desire to save $$$, but only if it is going to be of acceptable quality and durability in the long run.

Sending you a unit that will not work on your vehicle is not sounding like a company that I would want to be spending this kind of money with.
Their order process should be asking you ALL the possible information needed for them to match you up with the correct unit, first time.