These things wear out because they don't run in bearings. When Randy rebuilds an airbox, he installs Nylatron bearings. Smoother operation and will last a long time. https://en.wikipedia.org/wiki/Nylatron
Randy Rubbert
Rubbert Aircraft Maint & Repair
1850 2nd Ave NE
Reynolds, ND 58275-9477
Call: 701-847-3008
A friend took time out from brewing beer and building a Carbon Cub to make me a new shaft, and another friend who owns a company that makes control cables put a real end on my carb heat cable