Description
Cyma M4 Gearbox
This is a replacement gearbox for Cyma M4-pattern AEGs. Cyma is a popular manufacturer of affordable, dependable airsoft rifles, and its M4 range is widely used by new and experienced players alike.
If the gearbox in your Cyma M4 has failed, a factory replacement is often the quickest and most cost-effective way to get the rifle back in the game. It also makes a useful spare for players who run several Cyma M4s or who prefer to swap gearboxes rather than repair them on the day.
About M4 gearboxes
M4-pattern AEGs use the Version 2 gearbox design, which is the most common AEG gearbox layout. Parts and upgrades for it are widely available, so a factory Cyma gearbox can be used as it is or later upgraded with aftermarket springs, gears and pistons as your needs change.
Fitting
Fitting a gearbox means stripping the lower receiver, so remove the battery and magazine first. Take photos as you go and note how the wiring is routed. Check whether your rifle is front- or rear-wired, as this affects which gearbox you need. After fitting, set the motor height and test the gun with a chronograph before use.
Key features
- Replacement gearbox for Cyma M4-pattern AEGs
- Based on the common Version 2 gearbox layout
- Quick way to get a broken rifle working again
- Can be upgraded later with standard V2 parts
- Useful spare for regular Cyma users
Compatibility
Listed for Cyma M4-pattern AEGs. Gearbox wiring (front or rear) and small differences between models can affect fit, so check your exact Cyma model before ordering. Fitting to other makes of M4 may be possible but is not guaranteed.
Care and maintenance
Use good-quality seamless BBs and a suitable battery. Fire a shot on semi-auto before storing so that the spring is not left compressed. Keep the inner barrel and hop-up clean, and have the gearbox checked if you notice a change in sound or rate of fire.
Who is it for?
For Cyma M4 owners who need a replacement gearbox, and for players who want a spare to keep their rifle running.
Please note: Motor and battery are not listed as included. Check compatibility with your exact replica before ordering.
