Where is the output shaft speed sensor located on a 2001 Ford F-250?

The output shaft speed sensor (OSS) on a 2001 Ford F-250 is located on the tail housing of the transmission. Specifically, it's usually mounted on the driver's side of the transmission, near where the driveshaft connects.

However, the exact location can vary slightly depending on the specific transmission type (e.g., 4R100, E4OD). It's a good idea to consult a repair manual specific to your truck's transmission for the most precise location. A visual inspection after removing the appropriate undercarriage panels will generally reveal its location easily once you know the general area.