This procedure covers the removal and replacement of the output speed sensor on the 10R80 automatic transmission in a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine.

Warnings

Tools required

Parts

• Transmission output speed sensor × 1 — Use OEM Ford/Motorcraft specification
• O-ring seal for sensor (if not included with sensor) × 1 — Check if included with sensor assembly

Fluids

• Motorcraft MERCON LV ATF — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind front wheels
3. Raise rear of vehicle using appropriate jack points and support securely on jack stands
4. Allow transmission to cool if vehicle was recently operated
5. Position drain pan under transmission output speed sensor area on passenger side of transmission

Procedure

1. 1

   Locate the output speed sensor
   From underneath the vehicle on the passenger side, locate the output speed sensor on the transmission extension housing. It is positioned near the rear output shaft, typically with a single electrical connector and retained by one bolt. Clean the area around the sensor with shop towels to prevent debris from entering the transmission.
2. 2

   Disconnect the electrical connector
   Press the locking tab on the electrical connector and carefully pull the connector away from the output speed sensor. If the connector is tight, gently wiggle it while pulling. Do not pull on the wiring harness itself. Move the connector out of the work area.
3. 3

   Position drain pan
   Position your drain pan directly below the output speed sensor. When the sensor is removed, approximately 0.5-1 quart of transmission fluid will drain out. Ensure the pan is large enough and properly positioned to catch all fluid.
4. 4

   Remove sensor retaining bolt
   Using a 10mm socket and ratchet, remove the single bolt securing the output speed sensor to the transmission housing. Keep this bolt as it will be reused unless damaged. Be prepared for fluid to begin dripping once the bolt is loosened.
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)
5. 5

   Extract the output speed sensor
   Carefully pull the output speed sensor straight out from the transmission housing. There will be an O-ring seal on the sensor body. Once removed, allow residual fluid to drain into the pan. Inspect the old sensor for damage, metal shavings, or debris that might indicate internal transmission issues.
6. 6

   Inspect and clean the sensor bore
   Using a clean shop towel, carefully wipe the sensor bore opening in the transmission housing. Do not allow any debris or towel fibers to enter the transmission. Inspect for damage or excessive wear in the bore. Check that the old O-ring came out with the sensor and did not remain in the housing.
7. 7

   Prepare the new sensor
   Remove the new output speed sensor from its packaging. Verify it matches the old sensor. Check that a new O-ring is installed on the sensor body. Lightly lubricate the O-ring with clean MERCON LV transmission fluid to ease installation and prevent seal damage.
8. 8

   Install the new sensor
   Carefully insert the new output speed sensor into the transmission housing bore, ensuring it is properly aligned. Push the sensor in until it is fully seated against the housing. The sensor should slide in smoothly without excessive force. Do not rotate or twist the sensor during installation.
9. 9

   Install and torque the retaining bolt
   Install the sensor retaining bolt and hand-tighten it first to ensure proper thread engagement. Using a torque wrench and 10mm socket, tighten the bolt to specification. Do not overtighten as this can damage the sensor body or housing threads.
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)
10. 10

    Reconnect the electrical connector
    Reconnect the electrical connector to the output speed sensor. Push firmly until you hear or feel the locking tab engage. Gently tug on the connector to verify it is securely locked in place. Ensure the wiring harness is routed away from hot exhaust components and sharp edges.
11. 11

    Check transmission fluid level
    Measure the amount of fluid collected in the drain pan. With the vehicle still raised and level, access the transmission fluid check plug (located on driver side of transmission pan). Check fluid level per Ford procedure: with engine running, transmission at normal operating temperature, and in Park. Add MERCON LV fluid as needed to replace what was lost, typically 0.5-1 quart.
12. 12

    Lower vehicle and clear codes
    Remove jack stands and carefully lower the vehicle to the ground. Using an OBD-II scan tool, clear any diagnostic trouble codes related to the output speed sensor (typically P0722, P0723, or similar). This prevents false codes from triggering the check engine light during verification.

Reassembly

1. Ensure sensor retaining bolt is torqued to 12.0 Nm (9.0 lb-ft)
2. Verify electrical connector is fully locked and properly routed
3. Confirm transmission fluid level is correct using proper Ford checking procedure
4. Double-check that no tools or shop towels were left under the vehicle

Verification

• Start the engine and verify no transmission fluid leaks from the sensor area
• Shift through all transmission gear ranges (P-R-N-D) and return to Park
• Use a scan tool to verify the output speed sensor is reading properly and changes with wheel rotation
• Test drive the vehicle to confirm normal transmission shifting and speedometer operation
• Re-scan for diagnostic trouble codes to confirm none are present
• Perform final inspection under the vehicle for any fluid leaks after test drive

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