Speed Sensor failure

[Hoogz]

Hey guys,

Has anyone had any issues with there speed sensor? To explain.. Coming back on my trip to the cape last year the speedo started fluctuating and eventually stopped. It was lucky my GPS has the speed on it. Anyway, when I got home I did the dash systems check. Which all turned out fine, every thing responded. I checked the cabling going to the sensor, which also looked fine. So I concluded the sensor had stopped working. I ordered a new sensor and replaced it. The speedo came back to life. Thinking every thing was good I didn't think much more of it. Then about three to four months later the speedo stopped again. Which was a bit annoying as you would think it would last longer than a couple thousand KM. I managed to get another sensor under warranty. As jeep have a 6 month parts warranty. All good again, until today. I just so happened to get some unrelated parts from the local jeep dealer, when driving back the speedo stopped again?? Now its starting to get annoying! I should be able to another sensor under warranty. But I am wondering if there is a underlying problem? The only thing I can think off is either the sensors were a bad batch? Or the diff oil i use is causing a problem. But I wouldn't think so? As the sensor is a sealed? Has anyone else ever had any speed sensor issues?

[glend]

What year KJ is it? Petrol or Diesel?

[Hoogz]

Sorry, though my tag would have covered that. I have a 2003 2.5 Crd manual. I also have a Trac-loc diff centre. I just so happen to be doing a oil change on my diff this weekend so I will have a look inside too. Thanks

[DarrenR]

Re speed sensor..

two things:
*The wiring to the sensor plug (above the rear diff) is damaged somewhere.
*When you remove the diff cover plate, on the left side of the carrier you will see the tone ring (big ring with sort of teeth on it), see if its loose or damaged.

Regards
Daz

[cmohr]

Yes, had this happen before, replaced it and all good.

I know others that had similar problems, after replacing the sensor, and yes, it was the wiring harness that had a cracked wire, plus the plug itself had dirt and grit causing problems.