Mechbox VERSION TWO is arguably the most popular gearbox platform as it is currently in use by the newest releases of M4, MP5 and G3). The Advanced V2 Mechbox Assembly and Troubleshooting Guide teaches you how to properly put together and troubleshoot a V2 mechbox. Unlike most guides out there which base solely on the trouble-free TM implementation, our guide has been developed based on the assumption that you will be using a mixture of mechbox parts from different manufacturers, that there will be all sorts of compatibility & fitting issues and pitfalls (MANY of them) which have to be properly addressed along the assembly process. Instead of solely focusing on gear shimming, we pay close attention to MANY small and frequently-ignored details (in addition to shimming) that are in fact critical to the smooth operation of your mechbox. We also guide you through the steps required for achieving the best possible air sealing and compression effect.