Int. speedo-rough shift

[Drown]

Hello all,I just recently bought a 1993 Bronco with the 5.0 motor.

The vehicle has approx 160k miles on it but is in very good shape both mechanically and body wise.

Whats happening is that the speedo quits working and the trans starts shifting hard and reving high. My first suspicion would be the speed sensor in the driveshaft.The first time it happened I wiggled the connector and it cleared up.

Now it is doing it more often and no amount of wiggling-disconnecting-cleaning makes a difference.There is also a sensor in the transfer case if that makes a difference.

Anyone here familiar with this and can maybe point me in the right direction?

Is there a way for me to test the sensor with a meter to determine if it is bad?

The Haynes manual I have has no mention of the vss.

Thanks in advance fella's.

 

[Seabronc]

Sounds like you are right on top of it. You only get one speed sensor I'm afraid. If wiggling a wire worked before, then you probably have a broken wire, bad connector, or bad sensor. Try tugging on the wires to see if they come apart. Often wires corrode right where they go into the connector and brake or the contacts corrode. Be sure to seal it with dialectric grease when you finally fix the problem.

Good luck,

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[Drown]

Hey Seabronc,thanks for your input.

There really is a sensor in the transfer case,It is a vehicle speed sensor and I think it is a part of the e40d transmission circuit.I've read some other post's where people say it is supposed to have a plug in it,but sure as shit,there is a sensor in mine.

Now,after reading the schematics for the RABS circuit,I see that the speed sensor in the differential is a part of that.There are also two more speed sensors,one each for the front wheels. My question now is,could either of these sensors be causing this problem also?

Like I said,the speedometer quits working and the tranny acts goofy.

I will keep digging more into this and let you all know what I find.

 

[Drown]

Well,I did find the problem.A few inches back from the sensor itself,the wires looked as if they were kinked at one time and were going open intermittently.

I cut it open,stripped it back for some good wire and respliced it.Problem solved.

Thanks again SeaBronc.

 

[Seabronc]

Hey Seabronc,thanks for your input.There are also two more speed sensors,one each for the front wheels. My question now is,could either of these sensors be causing this problem also?

26137[/snapback]

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Sorry, I missed this post. Probably when I was on vacation. You are right about the extra sensorsin the wheels but as far as I can see they are not directly in the speed signal circuitry. They only let the RABS know what the wheels are doing so it can release some pressure if they are close to lockup. The module requires input from all three for the RABS. The transfer case or differential speed sensor feeds a parallel signal to the RABS and PSOM. Also the location of the speed sensor could be either in the transfer case or the differential depending, I believe, on the transmission or perhaps the transfer case that is installed, (maybe someone could clear that one up). Older trucks had a speedo gear in the transfer case and when they first switched to electronic speedometer they located the speed sensor in the transfer case. Later trucks located the speed sensor in the differential.

Enough rambeling :blink: . Glad you found your problem.

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