98 tranny on a 97 x

[SmokeGrinder]

Ok I just talked to my dealership on the phone. As you all may know i had a
98 5R55E tranny put in my 97 explorer and they no longer use the VSS but the ABS sensor to get the speed of the car.
my dealership are just about to change all the wiring so the car can get the apeed of the ABS sensor.
do you think this is going to work.....do you think the computer is going to understand this.

 

[dogfriend]

do you think the computer is going to understand this.

No.



I don't have any info on the 98 trans or engine control system, but it doesn't make sense to me that they would not use a VSS which is mounted on the trans or on the transfer case if you have 4wd.

I think the 97 computer will expect to see a signal from the VSS to control most engine functions.

Have they ever done this before?

 

[SmokeGrinder]

no they have never done this before, they say its all new to them. they want to run the eires to diffrent places they sound so sure its going to work..... they are a main ford dealership...

 

[dogfriend]

I don't think it will work....

This is my reasoning why:

The PCM (computer) is expecting to see a signal from the VSS to tell it how fast the vehicle is moving. It will use this information to calculate injector timing, transmission shift points, cruise control settings, etc. My 97 PCEM (Powertrain Control and Emissions Manual) says that a typical signal from the VSS is 125 Hz when moving at 55mph. The signal is generated by the VSS.

I couldn't find info on the signal generated by the ABS sensor, but unless it is exactly the same (and I don't think it will be) the PCM will be confused by the incorrect signal. The ABS sensor is reading an exciter ring mounted on the ring gear inside the rear differential. The ring gear will be turning much faster than the rear driveshaft (what the VSS is monitoring) - I don't think that the frequency of the signal will be the same as the VSS signal.

It occurs to me that they could be confused because the VSS is mounted on the transfer case - not on the output of the transmission. Make sure that they understand this before trying to reroute the wiring.

 

[SteveVB]

This makes no sense. As I understand it- you changed out the transmission, you reused the transfer case you had, which should be a 97 right. The VSS is on the transfer case as far as I know.

So why do they need to rewire anything. You have a 97 computer which reads the VSS which is on your 97 transfer case.

Im lost. SOunds to me like the dealer may be also. Maybe Im missing something.

Good Luck

 

[SmokeGrinder]

no i never reused the transfer case.... maybe i shoud do that?

 

[SmokeGrinder]

i just sent an e-mail to the dealership.....lets see what they say.

 

[dogfriend]

Originally posted by SteveVB
This makes no sense. As I understand it- you changed out the transmission, you reused the transfer case you had, which should be a 97 right. The VSS is on the transfer case as far as I know.

So why do they need to rewire anything. You have a 97 computer which reads the VSS which is on your 97 transfer case.

Im lost. SOunds to me like the dealer may be also. Maybe Im missing something.

Good Luck

I agree - I think the dealer is lost - smoking something - etc.

You must be using a transfer case - otherwise you won't have 4wd anymore. The VSS is mounted on the transfer case on a 4wd vehicle - otherwise the VSS wouldn't get the correct vehicle speed when in 4wd Low range.

 

[SmokeGrinder]

i am using the t case of the 98

crazy brits!

 

[SteveVB]

What waas wrong that you needed to replace the transafercase and the transmission?


And yes I would install the 97 transfer case if its operable so that you match your existing wiring. You are going to have no end of headaches if you start tearing apart wiring harnesses for no real good reason.

 

[SmokeGrinder]

i made a post before about what was wrong... when i took my foot off the gas on my old tranny it made a sound like a power saw...
I took the car to about 6 places and they told me they did not have a clue... i even took it to my ford dealership...

they dont really understand the car ayways as there are not many of them here in england. They expect it to be like a range rover and its nothing like that for sure!

i dont know what to do now :'( im just tired of spending money with people that dont have a clue what they are talking about i just want a car that works :-( I would love to have an explorer in the US where people know what it is...and how to fix it..

i called one place and told them i had a ford explorer and they said... whats that?? i mean thats how bad it is.

i go to college this year i really cant take much more of this.

 

[section525]

When I put a '99 tranny in my '96 I had to make a custom external tranny harness to match the internal one. Ford combined a few of the pins on the '99 interior harness so the '96 external one wasnt making the connections it needed to.

When you PMd me I thought you were 2WD for some reason. That's why I fed you that BS about tail shafts!

So just find a wiring diagram for the two trannies and make sure they're the same. If not, make the external one match the internal one. (I had to do that my conbining a few sets of wires). No prob.

 

[dogfriend]

I have the wiring schematic for the 97 - I can post it later when I get home from work ~ 7hrs from now.

Maybe someone can post the 98 wiring schematic also?

 

[dogfriend]

This is for a 97 transmission

 

[dogfriend]

page two

 

[dogfriend]

page three

 

[dogfriend]

page four (last)

 

[SmokeGrinder]

thanks guys i am just going to e-mail all this to my dealership.
I have no idea what i am going to do. if the ABS Signal is not the same as the 97 VSS then i have a problem. I guess i am going to have to take the X to the junk yard.

 

[section525]

The ABS is not the same. But it won't matter. As long as your computer is happy you can have all the VSS's you want.

All they did in the later model explorers was combine the ABS (rear) and the VSS. So as long as you have the VSS in the transfer case, which your 97 comp is looking for) it won't care whether its in the axle or not.

I say as long as your tranny harnesses match eachother you'll be good to go.

 

[SmokeGrinder]

just come off the phone with my dealership. they say the cant put the 97

Transfer case back on the 98 box because its physically different. The discovered last night that the signal from the ABS sensor would not keep the computer happy and that it was not going to work.

I mean if they say they cant change the Transfer case over that means they will not be able to get the VSS and as somone already said the signal from the ABS sensor is not going to be the same the the signal from the VSS.
any bright ideas.... my dealership say "Tom our only hope is that we find out on explorer forum"