Hyundai Repair: Innoperative Speedometer, driven gear, intermittent operation

Question
The speedometer of my Hyundai Sta Fe 2004 model w/ 4 cyl.engine have intermittent operation then it suddenly stop. Can you give an idea of the probable cause?

Answer
The most common cause of this condition is a worn plastic speedometer driven gear in the differential.  I recommend replacing the gear and sensor at the same time as either is prone to failure, either will cause the speedometer to not work, it's often difficult or impossible to diagnose the sensor itself, and the sensor portion sometimes breaks on removal.

The assembly mounts on top of the transmission differential with one 10mm bolt.  Once the bolt is removed, you should be able to twist the assembly and pull it out the top.