1995 Lexus GS 300 Driver's seat

The driver's seat will not move forward. It seems to sputter and angle when I try to move it forward. When I used a screwdriver to press in on the end of the drive shaft (opposite end of where the seat motor is located, and closest to the console), it seemed to work. Now it does not want to move forward, even though the motor is trying. Can that part be replaced here? Or do I need a whole new motor assembly.

Thanks for any ideas you have on this.