Previous installer probably forgot the petroleum jelly.
Turbine Shaft Speed (TSS) Sensor
Removal
1. Raise and support the vehicle. For additional information, refer to «Section 100-02».
2. Place a drain pan beneath the turbine shaft speed (TSS) sensor.
3. Remove the TSS sensor.
-Disconnect the TSS sensor electrical connector.
-Remove the bolt.
-Inspect the TSS sensor bore.
4. Inspect the O - ring seal for nicks or cuts; install a new as necessary.
Installation
Note:
Apply a light coat of petroleum jelly to the O - ring seal before installation.
1. Install the TSS sensor.
-Connect the TSS electrical connector.
2. Remove the drain pan.
3. Lower the vehicle.
4. Check the transmission fluid level, add Motorcraft MERCON® Multi - purpose automatic transmission fluid or equivalent meeting MERCON ® specification as necessary.
5. Start the engine and move the transaxle range selector lever through all gear positions.