Avantis Door Lock Gearbox Centre Case Replacement 45mm GenuineAvantis 45mm Replacement Door Lock Gearbox Centre Case A replacement centre case gearbox for the Avantis 45mm multipoint door lock mechanism. If you're having problems with your door lock, the gearbox is almost always the problem and changing it is as simple as removing a few screws. Information Important measurements: 45mm Backset 92mm PZ Centres This is the mechanism inside the door that is operated by the handle Most likely to be the problem when a