Gearbox Version 3

Gearbox Frame
This guide focus on disassembling the version 3 gearbox used in guns like most AK's, MP5K's etc. The fist step is to unpluck the motor, some special models (and shops) solder the wires to the motor. If the motor wires are soldered you can leave them on. Then remove the 2 screws holding the motor frame to the gearbox. Also remove the metal selector that connects to the selector plate. This is held in place with a single screw.

Motor frame
To get the motor out remove the screw and pry the 2 parts from each others. The frame consists of 2 metal parts holding holding it all together. The motor it self is a short version motor. A motor spring making sure the motor is fixed in position, and an ajustment screw to set the motor height (See the Shimming guide).

Open the box
The box it self has 4 screws holding it together. On the top is a metal clamp holting the entire top together, this bar is pulled out. This top metal clamping bar is one of the changes from the version 1 box.

The internals of the version 3 box, are almost the same as the version 2. The gears, cylender & head, piston & head, spring & guide, nozzlestyr, etc. are all the same. The main difference is the trigger assembly, and overall that is also kind of the same. To take it appart first remove the spring guide, spring and piston with piston head. Then lift out the 2 trigger parts (be aware that theres a spring underneath the trigger it self). Disconnect the nozzlestyr spring, and remove it, the cylender, and cylender head. And now you can remove the 3 gears (if you havent removed some already).

The switch
First remove the spring that pulls the trigger contacts apart. Then unscrew the small screw that holds the trigger contacts in the box. Remove the spring that pushes on the cut off leaver. Unscrew the cut off leaver, then remove the selector plate by moving it forwards.

The trigger contacts can be taken appart by removing the 2 screws. Remember to clean off any burn marks before reassembling!

When the gearbox is open I recommend the following mods: Angle of Engagement, Air pressure sealing, O-Ring Expansion, Short stroking, Electric system, Swiss Cheese. Most of them can be done on any gearbox and doing all the relevant ones will improve performance drastically. Also check out my shimming guide, because shimming is one of the most important jobs inside a gearbox!