2011 Impala LS. 56500 miles. Those pesky actuators go out every 4 years on an ACDelco part. And 1 to 2 years on every aftermarket part. But all of them are made with Chineseium materials. I replaced my actuator that just controls the recirculation door and just left it unplugged. The other heat door actuator has gone out 3 times now. Its easy to replace since i only have a single zone heat/ac. I decided to take the broken one apart and discovered of course one of the three plastic gears have broken teeth. Which i already knew. Well i had an epiphany. Why not 3D print some new gears and see if it works. So I went and bought a new OE actuator and took it apart. I removed the 3 plastic gears and took it to someone and had them made via 3D printing.  Well, Low and behold. It DID work and since its made out of a better material than Chinese plastic, I hope it lasts the life of the car. Not holding my breath though. Anyways, I thought this would be a good way to stick it to GM since they have been putting these god-awful actuators in everything they have. I hope more people try this out. I don't know how long this fix i came up with will last. If it doesn't last. I'm only out a half hour labor and 20 extra dollars. Thank You,   Jeff S