AC/Heater diverter box repairable?

[grebus1]

Has anyone been able to repair the flap inside the AC/Heater diverter box? This is the box inside the truck under the glove box. There is a door in the box that opens or shuts depending on whether you slide the control lever to AC or over to Heater. I have to replace the box on my Sub for the second time because the rod is spinning inside the flap and will not control it. This is not a cheap part (about $70-100)!