So my speedometer doesnt work anymore. Every once in a while it will work but its usually after hitting a big bump or something. could it be the speedometer gear?, Cable? or the actual gauge?

 

Check the connections at the speed sensor. Remove wire connection clean the terminals. This would be if you have a late model Cherokee. I don't know about older Cherokees.

 

My XJ is a 1992

 

Is this a speed sensor driven type or Gear type ( look at the rear of the tranny to determine type ) Wires = Speed Sensor / Cable most likely a gear driven type, check all connectors leading to ......

 

do the gears ever go bad?

 

Can and do- Yours is electronic , Check the grounds on the block by the oil dipstick. One of them grounds the speedo at the panel

 

so i followed the wires and couldn't find a ground on the block to save my life. so i went back to the sensors and unplugged the connections to see if they were dirty. in the process i discovered the actual sensor was loose on the transfer case. tightened it up and speedo works again