My speedometer is not working after replacing the ring & pinion in the differential.

[abadk9420]

I have a 94 Aerostar and me and a friend just replaced the entire differential and pinion gear and now my speedometer is not working, occasionally it will work speractly and bounce around, also my ABS light is on, my cruise control does not work, and it will not shift into overdrive, any help and pictures would be very helpful. I was thing it might be the wheel speed sensor that runs off of the sprocket looking thing attached to the ring gear, but I really have know idea.

Thanks,
Curtis

 

[BrooklynBay]

Welcome to this forum! Did you connect the sensor on the top of the differential?

 

[Foxracin]

Yep, make sure its still connected like BrooklynBay said and make sure when you disconnected it you didnt pull one of the wires out half way or so where it isnt getting a good connection.

 

[jayXnaranjo]

You know, I have the same problem with my 98 Explorer. The speedo and odometer just stopped spinning one day. I replaced the sensor at the top of the diff but that wasnt it. an electrician told me it might be the dash that is not working. have you taken it to an electrician? regardless, I just left it like that. the ABS light does indicate that your anti-lock braking system is not working and to let you know that there is an electrical failure somewhere. About the overdrive, you got me stumped there friend...sorry i couldnt be much help. hope it all works out. :rangertan:

 

[BrooklynBay]

The PCM needs a speed signal to tell it when to engage overdrive (3-4 shift solenoid), and engage the TCC solenoid.

 

[abadk9420]

As far as I know we never unhooked the sensor, but I am thinking that maybe because there was no oil in the diff that maybe it just burned up from the excessive heat, when we took it apart there were no teeth left on the pinion gear and all of the diff oil that was in there was baked on to the parts and full of metal shavings, I just don't get why every once in a while the speedometer will start working kinda half ass, I know that the both it not going into overdrive and the cruse control not working are directly related to the speedometer not working, and I am thinking that may also be why my ABS light is on, do any of you have a picture of where the wheel speed sensor is located on the diff housing. I don't have a manual and do not have the funds to get one at the moment because I am laid off work.

 

[BrooklynBay]

It's on the top of the differential. Only one bolt holds it in place. Check my sticky thread on ABS codes: http://www.explorerforum.com/forums/showthread.php?t=241825

 

[abadk9420]

So are there 2 different sensors in the rear diff housing? Because I have found both a wheel speed sensor that looks like it has teeth on it that seems like it would be turned by what looks like a sprocket attached the ring gear, as well as a rear ABS sensor.

http://www.autozone.com/autozone/pa...1ehZ9gsum?counter=0&itemIdentifier=68815_0_0_

http://www.autozone.com/autozone/pa...koh2?counter=0&itemIdentifier=352012_55326_0_

 

[BrooklynBay]

The part in the second link is the one that's used on the differential.

 

[abadk9420]

Does that piece on the end of the sensor get turned by what looks like a sprocket attached to the ring gear?

 

[BrooklynBay]

The inside of the sensor has a magnet, and no moving parts. It works on the Hall Effect principle of an expanding & collapsing magnetic field. The differential's internal gear has teeth which cause this change within the sensor. Check these links: http://en.wikipedia.org/wiki/Hall_effect http://en.wikipedia.org/wiki/Hall_effect_sensor

 

[abadk9420]

So then what is the other sensor for and where does it go on my van?

 

[BrooklynBay]

The older models use a gear driven VSS on the rear driver's side of the transmission's extension housing (except when there is a transfer case). Check # 3 in my list of useful threads for more information: http://www.explorerforum.com/forums/showthread.php?t=158739

 

[abadk9420]

Thanks, do you think that could the root of all of my problems? Before we did any work to the diff the speedometer, cruse control, and Over drive all worked fine and there was no ABS light on.

 

[BrooklynBay]

It's possible, so check this sensor, wiring, and the internal ring gear.

 

[abadk9420]

Is the internal ring gear that you are talking about the gear that kinda looks like a sprocket, and is attached to the the actual ring gear that is turned by the pinion gear?

 

[BrooklynBay]

Yes.

 

[abadk9420]

Turned out to be the ABS wheel speed sensor and while we were out at pic n pull grabbing a starter we found one that was in like new shape, the old one had gotten chewed up by all the metal shavings from when my pinion and ring gears had gotten fried, there was fine copper wire hanging out of it, it looked really bad. I will post a pic of it later if I can, Just glad everything is all fixed again and all of my idiot lights are out on my dash.

 

[BrooklynBay]

Thanks for the update!

 

[abadk9420]

Thanks for the help...