This gearbox is a classic bestseller, known for its exceptional durability and low weight.
The QSC (Quick Spring Change) feature makes upgrading and maintaining your replica far easier.
The split functionality adds even more convenience, allowing users to diagnose, repair, and exchange parts in the upper gearbox without ever having to take the entire gearbox out of the lower receiver.
According to Retro, these shells were designed to be fully compatible with TM parts.
Manufacturer notes:
CNC split gearbox V2 designed for airsoft replicas AR15 (M4), M16 and other ones with V2 gearbox.
This gearbox is manufactured from one solid block of aircraft aluminum (Dural) EN AW 7075 T651, which has higher strength (590MPa), than common construction steel (390MPa).
Because of used material, our gearboxes have the best durability and resilience than common zinc-aluminum gearboxes. We are manufacturing these gearboxes on our precise CNC milling machines in our factory.
Detail in bracket (8mm) means diameter for bushings/bearings. Split gearbox means that this gearbox is designed with two parts: Upper and Lower. Having a split gearbox has many advantages. For example: much easier installation of the inner parts into the gearbox.
During installation of a cylinder set, there is no need of removing the whole gearbox from your receiver, only the upper part can be dismounted because its mounted on one receiver pin. This gearbox can be installed even into the receivers AR15 (M4), what are not completely straight, with any AR15 (M4) Hop-Up chamber of your choice. The recommended nozzle length is 21.4mm. Be aware that nozzle length can be influenced by many factors, for example angle of the tapped plate or different length of front part of the Hop Up bucking. In these scenarios, you will need a different nozzle length.
Package includes: CNC Split Gearbox V2 (8mm) – QSC in chosen color, set of screws and QSC spring guide.
We made some useful improvements into our CNC split gearboxes V2:
- Spring holders have grooves, so the springs for tapped plate and trigger switch will not jump off.
- Added groove for safety lever, so it will hold during installation.
- Added groove for trigger spring, for better fitting.
- AOE control hole.
- Sockets for bushings/bearings have smaller diameter about -0,02mm (7,98mm), for non-overturning the bushings during installation. The socket edges are cut down for better installation.
- We enhanced grooves for wiring for 1mm, you can now use wirings with 2,5mm diameter. - Added protecting edge for wiring against the motor.
- All threads are now shaped instead of cut for better strength.
- Both of the gearbox parts are centered by milled grooves and edges.
- Added hole for releasing anti-reverse latch.
- For better durability, we added more material around cylinder head part of the gearbox, this was the most critical part and we added 100% more material where is huge radius.
- Added groove for anti-reversal latch spring, so it will not jump off.
- Outer edges are now cut off.
RetroArms gearbox has quick spring change system (QSC), where you can remove the whole spring guide with a hex key and change the spring without opening the gearbox. In this solution, you need to secure spring guide with screw, commonly with AR 15 (M4) replicas, it is by stock screw. In situations where you have folding stocks or no stock at all, you have to secure the spring guide with QSC screw. Otherwise there could be situation, where the spring guide will stuck with the spring. This is because the spring guide is not fixed in the gearbox but has will for easy removing with hex key.
Space for trigger switch is designed for compatibility with trigger switches, trigger units from common manufacturers for example: Gate, etc. CNC gearbox V2 has protective anodizing, even when it is problematic to anodize aluminum EN AW 7075 T651 (Dural), because of its high strength and hardness. If we did not anodize products from this material, there is huge risk of corrosion (huge gray spots with rotten look).
CNC gearbox can be installed only in Airsoft replicas with Tokyo Marui compatible standard. That means even the inner parts. Do not use brute force during installation. Use only 1Nm tightening moment on screws, otherwise the screws will overturn in heads. There is no need of tightening screws with brute force, if you want to be sure that screws will sit perfectly, use thread glue or thread locker.
You can use in our CNC gearbox any spring of your choice, but be aware that stronger springs will result in lower durability.
!! do not use MAXX cylinder head !!
Installation of the inner parts and gearbox requires professional knowledge, experience and skills. There are a lot of Airsoft manufacturers on the market and every one of them create their own sizes, there are no standards like engineering ISO in Airsoft. This is the main problem with a lot of inner and outer parts from different manufacturers which can be same product, but with different dimensions. We recommend using only parts from manufacturers with Tokyo Marui compatible parts, where should not be a problem with compatibility with our CNC gearbox.
