98' explorer goes into 4x4 on dry pavement

[OLDSETTER]

I need some help on testing my axle speed sensors. My Explr goes into 4x4 and binds up (of course). This 98' limited has the Auto, high, and low setting on the dash. This happens in Auto. I disconnected my brown wire so my transfer case would not explode. It only happens intermittently - like most of my problems. I also get flashing 4x4 light on the dash, I don't have a code reader, but would like to test the front and rear axle speed sensors (hall effects?). I have not seen anything like this on the net. Anyone else heard of this problem and/or know of a fix? Any guidance would be appreciated.

Thanks,
Oldsetter.

 

[OLDSETTER]

I gave up on trying to fix this myself. I took it in for the cruise control recall and had the tech look at the 4x4. He said the motor was bad, the input and output switch and it needed a wire harness w/resistor.....for just under $1000 parts and labor. That is not what I wanted for xmas. And they wonder why we hate them? We know there is nothing wrong with the motor because I cleaned it up from what I learned on this site and it was working. But does anyone know about this input and output switch and resistor wiring?
Thanks,

 

[gijoecam]

Can't speak to the switch or the wiring, but I can guarantee it's not the motor as the motor has absolutely nothing to do with the automatic 4wd or the transfer case lock-up. I wish I could be at the dealership to ask the questions when they tell people that a second-gen Explorer needs a shift motor because the 4wd won't engage. Drives me ape-sh*t!

What they needed to do was hook up a diagnostic monitor to the GEM and take it for a drive, watching to see what the GEM sees from teh speed sensors on the transfer case and rear end, and see exactly what's triggering the 4wd. If they can't provide you with the info that says exactly WHAT is causing the 4wd to engage, they haven't done enough testing IMHO. They should be able to say, "The system is seeing the rear wheels slip and calling for the 4wd."

It's ridiculous..... shift motor... pffft! Whatever!

 

[rhyno]

I am having the same issue right now on my 97, so its been sitting for over a week. I hope to get to it this weekend though. This happened before about 5 years ago too, and the dealership replaced both front and rear speed sensors. Anybody know an estimate cost on those suckers, and how hard it would be for me to swap them out myself? Thanks.

 

[NHale623]

At the dealership, I believe the hall sensors are around $50 each. You'll do much better at fastpartsnetwork.com.

They are relatively easy to replace. The rear sensor is a snap, the front sensor is behind the shift motor. You gotta remove the shift motor to gain access to the sensor.

One bolt on each sensor.

Before you replace the sensors, just remove them, clean with a soft rag, reinstall and test. Sometimes they'll get dirty and not function very well.

If you're going to replace them, the fun part is disassembling the wiring connector on the shift motor to remove the old sensors and install the new sensors correctly in the connector.

You will not need any special tools. Sockets, needlenose pliers (for the connector) and a very small screwdriver to remove the pins from the connector. You do not need to drain the TC fluid. Though you might as well do it while you're underneath there.

 

[rhyno]

Thanks for the info NHale. I will try cleaning them before purchasing replacements.

 

[OLDSETTER]

Yeah, I knew there was nothing wrong with the motor. I never act like I know anything about cars around a dealership as a 'test'. If they can not explain what the '$800 frimastat' has to do with the symptom, I thank them for the diagnosis and go my way. If they seem honest, I'll let them do the repair. I will try to clean my switches first. I don't know what the resistive wire harnes if for though.