CYMA Sport Complete 8mm Version 2 Gearbox for M4 Series Airsoft AEG (Type: Rear Wired / No Motor)

Upgrade your AEG’s internals with precision, durability, and reliability — the CYMA Sport Complete 8mm Version 2 Gearbox (Rear Wired / No Motor) is designed to deliver consistent performance straight out of the box. Whether you’re rebuilding an old rifle, assembling a new custom M4, or simply replacing worn-out internals, this gearbox provides a strong and dependable foundation for your airsoft platform.

As one of the most trusted names in airsoft manufacturing, CYMA has earned its reputation for building robust, field-ready components that stand up to serious gameplay. This Version 2 complete gearbox is no exception — engineered for players who demand smooth operation, superior durability, and easy compatibility.

Built for Strength and Reliability

At the core of this gearbox is a reinforced metal alloy shell — designed to handle the stress of upgraded springs and high-torque setups. The solid construction prevents cracking and flexing under heavy load, ensuring your gearbox maintains alignment and compression integrity even during sustained automatic fire.

CYMA’s precision manufacturing guarantees tight tolerances and consistent gear alignment, helping minimize internal friction and mechanical wear. The result? Smoother cycling, reduced vibration, and a longer service life for your AEG.

8mm Metal Bushings for Maximum Efficiency

Equipped with 8mm metal bushings, this gearbox promotes smooth, efficient gear rotation while reducing friction and heat buildup during high-speed or high-torque operation. Compared to smaller or plastic bushings, these durable metal components ensure stable gear alignment and lower wear on your drivetrain — ideal for players looking to tune their rifle for optimal performance.

The inclusion of a ball bearing metal spring guide further enhances efficiency, helping reduce spring tension during compression and decompression cycles. This not only smooths out the gearbox’s performance but also improves overall trigger response and rate of fire.

Low Resistance Wiring for Better Electrical Flow

The CYMA Sport gearbox comes pre-wired to the rear with low-resistance wiring, ready for plug-and-play installation in M4/M16-style AEGs. The small Tamiya connector ensures wide compatibility with standard airsoft battery setups, including rear-stock configurations.

Low-resistance wiring reduces electrical loss between the battery and motor, providing more consistent voltage delivery for snappier trigger response and improved efficiency. Whether you’re running a NiMH or LiPo battery, this setup ensures you get the most out of your power source.

Perfect Foundation for Custom Builds

Whether you’re building a high-torque DMR, a high-speed CQB rifle, or a balanced all-around AEG, the CYMA Sport Version 2 Gearbox serves as a reliable base. Its standard Version 2 configuration is compatible with most M4/M16 AEG platforms, allowing seamless integration with aftermarket upgrades and tuning parts.

Pair it with your preferred motor and internal components to achieve your desired performance specs — this gearbox is fully upgradeable and ready to evolve with your build.

Easy Drop-In Installation

Designed for ease of installation, this gearbox arrives pre-assembled and ready to install. Simply drop it into your M4 or M16 receiver, connect your motor and battery, and you’re ready to hit the field. CYMA’s precise design ensures proper fitment, making it an excellent option for both beginner technicians and seasoned airsoft builders.

Specifications:

• Manufacturer: CYMA

• Compatibility: Most Version 2 M4 / M16 AEGs

• Type: Rear Wired (No Motor Included)

• Bushing Size: 8mm Metal Bushings

• Spring Guide: Ball Bearing Metal Guide

• Material: Reinforced Metal Alloy Shell

• Connector Type: Small Tamiya

• Wiring: Low Resistance, Rear Wired

• System: Full Metal Version 2 Gearbox Assembly

Why Choose the CYMA Sport 8mm Version 2 Gearbox?

✅ Reinforced gearbox shell for durability
✅ 8mm metal bushings for smooth performance
✅ Ball bearing spring guide enhances efficiency
✅ Rear-wired setup for easy compatibility with M4 AEGs
✅ Preassembled and ready for plug-and-play installation

About CYMA

Founded in 2000, CYMA Airsoft is a leader in producing high-quality airsoft guns, gearboxes, and components for players and training professionals worldwide. With expertise that extends beyond recreational airsoft, CYMA collaborates with real steel firearms companies to produce realistic training weapons for law enforcement and military applications.

CYMA’s mission is to blend innovation, precision engineering, and durability — ensuring every player can trust their equipment to perform in any environment. When you choose CYMA, you choose reliability, performance, and battle-tested engineering.