Where on the transmission is speed sensor unit located a 96 Chevy lumina?

On a 1996 Chevy Lumina, the vehicle speed sensor (VSS) is typically located on the output shaft of the transmission, near the transmission tail housing. It's usually a single sensor with a single wire connector. However, the exact location can vary slightly depending on the specific transmission type (automatic or manual) your Lumina has.

To be certain, you'll need to consult a repair manual specific to your Lumina's year, make, model, and transmission type. A Haynes or Chilton manual would be helpful. You can also search online for diagrams or photos of the transmission on your specific model Lumina. Looking at a diagram will give you the best visualization of its location.