How To Replace The Speed Sensors On A 1999-2004 Jeep Cherokee

The transmission for a Jeep Cherokee has two speed sensors on it to regulate how the transmission works. There is the input and output speed sensors. If one or both of the sensors fail, your transmission will start to idle roughly and the Jeep can start to jerk around when driving. You need to replace the sensors to get the Jeep running well again. This is a job an amateur mechanic who knows how to set the Jeep up on jack stands can do in their driveway in under an hour. If your speed sensors are bad on your transmission, here is how you can replace them.

You Will Need:

  • Two Speed Sensors
  • Ratchet
  • Short Extension
  • 8mm Socket
  • 1/2" Open-Ended Wrench
  • Jack
  • Jack Stands

Jack Jeep Up

If you are small enough, you might be able to slide right under the Jeep without raising it up to change the sensors. However, if you need more room, jack the Jeep up and set in on jack stands.

Sensor Locations

Slide under the car until you get to the bottom of the transmission. You will see a label on the bottom of the transmission that lists the part number and bar codes for the transmission. The input sensor is located just above the top right-hand side of the label and the output sensor is located off of the top left-hand side of the label.

The sensors will have a thick electrical cord running to them, and each one is held to the bottom of the transmission with an 8mm bolt. The sensors have a plastic housing that is about the size of the palm of your hand.

Remove Sensors

The input sensor is a little harder to remove than the output one because there is a cable in the way. You need to unbolt the bracket for the cable so you can remove the input sensor. Use the 1/2" wrench to remove the bolts. Once the bolts are removed, simply push the cable to the side.

You can now remove the 8mm bolt on the bottom of the sensor with your ratchet and socket. Unclip the electrical cord going to the sensor by pressing down on the clip and pulling the cord off of the top of the sensor. Pull the sensor out of the transmission.

Remove the bolt on the output sensor and unclip the electrical cord. Pull this sensor out of the transmission.

Installing New Sensors

Place some transmission fluid of the same type you are using in the Jeep, or use some penetrating oil, and coat the gaskets on the sensors to moisten them. Set the sensors in place of the old one and bolt them in place. Clip the electrical cord back onto the top of the sensors. Bolt the cable bracket back in place by the input sensor to finish the job.

If you feel you cannot do this on your own, take your car into a transmission repair shop.