Aero Tree has been rebuilding Air Locks/Feeders since 2010. We started in this business because there were 20 Mulch Blower trucks in Palm Beach County. Mulch companies tried other machine shops to have the Air Lock/Feeders rebuilt but it didn't work out. Aero Tree was able to fill that need. Here we try to maintain .020-.030 clearance between rotor and box so it's a tight clearance. You need to have your auto revering working good. If not feeder will lock up. Locking up is not because of the rebuilt feeder, a new feeder will be the same. It is very important for your auto revering to work.