I have a 1999 XJ 4.0 6 cylinder. My speedometer doesn't work, I know its not any problem with the dash because it threw up[ a code for the speed sensor. I'm just wondering where the speed sensor is located? I cant seem to find anything online for my year that points out where it is and how to replace it. Thank you!

 

Back of the transmission if a 2wd, back of the xfer case if a 4wd.

 

Does anyone know what speedometer gear teeth number I need to correct a 2000 speedometer running 35&4.56 gears?

 

37-tooth going by the charts. https://www.google.com/search?client...edo+gear+chart

That's assuming typical tire diameters, which can be off depending on the tire, wheel, etc. You can get a better answer if you use a GPS app on your phone and see how far you're off now versus what gear you currently have.