General Maintenance & Repairs - Headlights gone crazy

My girlfriend has a 2001 Firebird and her headlights were grinding so we replaced the gears. It stripped the gear in the driver's side again, so we replaced the whole motor. Now, the headlights won't get in sync, i.e. the passenger side is up when the driver's side is down. No matter what combination of headlights being up and/or down I can arrange, the headlights won't sync. It's like the sensor is telling them to go up and down at different times. The arm connected to the motor is aligned the exact same on both headlights. Please help.

Did they work correctly when you replaced the motor originally? If so:

95% chance that when you put one of the lights back on, the actuator arm didn't get on the motor shaft correctly, isn't seated all the way down, and its not engaging the stop correctly. (Watch the good light and how the arm rotates around to hit the metal stop. The other side should do the same.)