Well we have a Cedar Creek 38FL and the air return vents are located over our bed. They are installed with 2 wood screws - one of which appeared to be not holding on to anything. Well it was finally time to clean the filters. I knew this was going to lead to some additional work....
1. Removed the screws - one screw was not even into the wood. Just kinda hanging on to the cardboard for the filter.
2. Cleaned filters and vents
3. Drilled new holes for 8/32 screws
4. Mounted the screws sticking down and put fender washer on each side of the wood panel. Added a nut and tightened down.
5. Put the vents and filters back up and then used cap nuts over the screws to keep everything together and easy to remove next time for cleaning.
Total cost about $3.00
These were attached to the ceiling with wood screws originally.