Hi folks,
I bought my 89XJ in December and the speedometer has never worked. It would occasionally make a loud metallic grinding sound for periods of time (only when moving) and then stop. The needle was stuck under the "85" and just jerked a little.
I removed the instrument cluster and drove the Jeep and the speedometer cable spins fine in the housing.
I took the speedometer out of the instrument cluster and tested it with a screwdriver. Here is a link to a video of me testing it and identifying what I think might be wrong with it.
https://vimeo.com/59871388
Thanks for your help.
-Matt

 

Sounds like issues at other end unscrew cable and spin it with a drill under neath ,souunds like cables brooke to me.

 

Thanks for offering ideas. As I mentioned, I know that the cable from the transfer case is working fine. It is the speedometer device itself that is causing the needle to jump.

 

It also could be your cluster ground is bad... Clean it and re attach it

 

Speedos mechanical not electrial ....

 

When cables start to go bad or dry out from no lubrication they start to fray which causes them to catch inside the housing causing the jumping ffect . From you video you can see the smooth movement off spedo matching your turns with screw driver . that why you attach axdrill and spin cable if speedo jumps still its the cable .If not could be damage gear in housing . Just sharing years of automove service with ya .