Blend Door linkage failure?

Hello, thank you for the reply. The gear I am describing is the white gear that couples to the blend door actuator gear. This gear is supposedly part of the blend door and to repair this the door needs to be replaced, then a new actuator motor. Is there a way to access this door and secure it to the heat position, as if to pull off one panel and put a screw in it? I do not like to make a hokey fix but from what I'm told the entire heating system and the dash needs to come off just to replace this door and that's a few thousand from what I'm told. Any direction on how to fix this temporarily or permanently without ripping out the dash is much appreciated. Thank you for your time and advice.

I wish I could upload a photo, but just yesterday I had my mechanic turn the blend door to max heat and reassemble the bled door actuator back on the blend door gear and I'm getting really good heat in the present cold weather. I do not want to jeopardize it. The door gear is like the female side where the door actuator gear is set into it. The splines of the door gear are a cheap white plastic that breaks off and the actuator gears don't mesh. Adjusting this damper with a screwdriver is something I can do myself but my mechanic can do it quicker at the time of an oil change visit; warm the motor, plug in the blend door power connector and gradually and carefully rotate the temperature dial on the dash back and forth until you feel the damper move to max heat then unplug the power connector. In the summer repeat the process to get cold air. My goal is to get it fixed properly but not if ripping out the dash and buying an entire heating system is going to cost me thousands. When and if the gear becomes unable to turn, I will have my mechanic apply a removable Permatex type adhesive or RTV between the two gears.