Transmission Speed Sensor - Output

Replace the output speed sensor on the Borg-Warner T56 6-speed manual transmission by accessing it from underneath the vehicle, disconnecting the electrical connector, and removing the sensor from the transmission housing.

Warnings

Tools required

Parts

• Transmission output speed sensor × 1 — Mopar 4800879 or equivalent
• O-ring seal for speed sensor × 1 — Usually included with sensor

Preparation

1. Park vehicle on level ground and apply parking brake firmly
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool if vehicle was recently driven (minimum 30 minutes)
4. Gather all tools and new parts before beginning work

Procedure

1. 1

   Raise and support vehicle
   Using a floor jack at the front crossmember, raise the front of the vehicle to a comfortable working height. Immediately place jack stands under the factory jacking points behind each front wheel. Lower the vehicle onto the jack stands and verify stability before proceeding. The rear can remain on the ground for this procedure.
2. 2

   Locate output speed sensor
   Position yourself under the passenger side of the vehicle near the transmission tunnel. The output speed sensor is mounted on the right (passenger) side of the T56 transmission tailhousing, approximately 12-14 inches forward of the driveshaft yoke. It will have a single electrical connector with a locking tab.
3. 3

   Disconnect electrical connector
   Locate the gray electrical connector on the output speed sensor. Press the locking tab on the connector body while pulling the connector straight away from the sensor. If the connector is difficult to remove, use a flathead screwdriver or pick tool to carefully release the locking tab. Wipe away any accumulated dirt or debris from around the sensor body.
4. 4

   Remove sensor mounting bolt
   Using a 10mm socket and ratchet, remove the single bolt securing the output speed sensor to the transmission housing. Place the bolt in a parts tray to prevent loss. Place the bolt in a parts tray to prevent loss.
   Torque spec

   Sensor Bolts11 Nm (8 lb-ft)
5. 5

   Extract sensor from housing
   Grasp the sensor body firmly and pull it straight out of the transmission housing bore. A slight twisting motion while pulling may help break the O-ring seal. Expect minimal transmission fluid seepage (typically just residual fluid on the sensor). Have a shop towel ready to catch any drips. Inspect the sensor tip for metal debris or damage.
6. 6

   Prepare sensor bore
   Wipe the transmission housing bore clean with a shop towel. Inspect the bore for any debris, metal shavings, or damage to the sealing surface. Remove the old O-ring from the sensor bore if it remained in the transmission rather than coming out with the sensor.
7. 7

   Install new sensor
   Verify the new O-ring is properly seated in the groove on the new sensor body. Lubricate the O-ring lightly with clean transmission fluid. Align the sensor with the transmission housing bore and push it in firmly by hand until it seats flush against the mounting surface. The sensor should insert smoothly without binding.
8. 8

   Install and torque mounting bolt
   Thread the 10mm mounting bolt by hand to ensure proper thread engagement. Using a torque wrench, tighten the bolt to specification per the torque spec list.
   Torque spec

   Sensor Bolts11 Nm (8 lb-ft)
9. 9

   Reconnect electrical connector
   Push the electrical connector onto the new sensor until you hear and feel the locking tab click into place. Tug gently on the connector to verify it is fully locked. Route the wiring harness away from any sharp edges or heat sources.
10. 10

    Lower vehicle
    Raise the vehicle slightly with the floor jack to unload the jack stands. Remove both jack stands and carefully lower the vehicle to the ground. Remove wheel chocks.

Reassembly

1. No disassembly of other components was required for this procedure

Verification

• Start the engine and verify no check engine light illuminates
• With the vehicle in neutral and clutch engaged, verify the speedometer reads zero
• Test drive the vehicle and confirm speedometer operation is normal
• Check underneath the vehicle for any transmission fluid leaks around the sensor
• If available, use a scan tool to verify the PCM is receiving output speed sensor signal (should read approximately 0 MPH at idle in neutral, and match vehicle speed when driving)

Related trouble codes on this vehicle

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