2007 8-way Power Seat Motor

[jwhitesides]

I have a 2007 Yukon Denali w/ 8-way power adjustable seats. The feature that moves the front part of the seat is not working. The switch works, the motor works, and I am able to see the rotation of something on the end of where the worm gear connects to turning. But the worm gear itself is not turning and in turn not moving the front part of the seat up or down. Does anyone know what may be causing this?