M4 Complete V2 Gearbox

£34.95

Complete, fully assembled Version 2 gearbox: a true drop-in replacement
Full metal shell built for M4, M16 and AR-type AEG rifles
Steel gear set running on metal bushings for reliable cycling
Supplied with gears, piston, spring, shims, trigger contacts and wiring
Standard V2 layout with the motor seated in the pistol grip
A cost-effective way to rebuild or replace a tired or dead gearbox
Not a quick-change spring type: a sealed, ready-to-run assembly

Hurry! Only 1 unit left in stock!

Guaranteed Safe Checkout

Why Buy From Platoon Stores

In-House Repair Workshop in Rochester Kent

Kent's Only Authorised 5.11 Tactical Retailer

UKARA Registered Retailer

What our customers are saying

Be the first to leave a review.

Write a Review

There are no reviews yet.

Description
Specification

A complete drop-in gearbox

The DBoys M4 Complete V2 Gearbox is a ready-to-run Version 2 unit supplied fully assembled with gears, bearings, piston, spring, shims, trigger contacts and wiring already in place. Rather than sourcing individual parts and building from an empty shell, you drop this straight into your M4, M16 or AR-type AEG and get back on the field faster.

Full metal shell and steel gears

Built around a reinforced full metal V2 shell, the gearbox pairs a steel gear set with metal bushings for dependable cycling under normal skirmish use. It is a sensible, budget-friendly choice for anyone rebuilding a rifle after a gearbox failure or upgrading from a cracked polymer or worn shell.

Standard V2 layout

This follows the classic Version 2 architecture: the motor sits in the pistol grip, the selector plate runs down the side and the mechanical trigger contacts live inside the shell. That means broad compatibility with the huge V2 aftermarket if you later want to tune gears, cylinder or spring.

Please note before ordering

This is not a quick-change spring type, so spring swaps need the shell opened up. There is no MOSFET fitted. If you would rather we install, shim and test it for you, our Kent workshop can help via our airsoft repair service, and you can find matching internals in our airsoft accessories range.

Product information reviewed by James Smith. Every gun is checked & serviced by our Rochester workshop before dispatch.

General
Brand	DBoys
Other
Compatibility	M4, M16, AR-type AEG rifles
Shell material	Full metal alloy
Assembly	Fully pre-assembled, drop-in
Type	Complete Version 2 (V2) gearbox
Gears	Steel, standard ratio
Bushings	Metal
Piston	Included, pre-installed
Spring guide	Fixed, not quick-change
Motor position	Pistol grip (standard V2)
Trigger system	Mechanical trigger contacts (no MOSFET)
Connector	Mini Tamiya (typical)
Condition	New

Recommended upgrades & accessories

Frequently asked questions

Will this fit my M4 AEG?

It suits the vast majority of M4, M16 and AR-type AEGs that use a standard Version 2 receiver, such as G&G, JG and CYMA. Minor shimming or fitting may be needed as tolerances vary between brands, and you should match the wiring orientation to your rifle.

Is it front-wired or rear-wired?

DBoys produce both front-wired (battery in the handguard) and rear-wired (battery in the stock or buffer tube) V2 shells. Check the wiring exit on your rifle before fitting, or ask our workshop and we will confirm compatibility.

Does it include a MOSFET?

No. This is a standard mechanical unit with trigger contacts. If you plan to run a high rate of fire or an 11.1V LiPo, we recommend adding a MOSFET to protect the contacts from wear and arcing.

Can I quickly change the spring?

No. This gearbox uses a fixed spring guide, not a quick-change (QD) rear guide, so a spring swap requires full disassembly of the shell. If you want tool-free spring changes, look at a QD gearbox instead.

What FPS will it produce?

Muzzle energy depends on the fitted spring, your inner barrel length and air seal. Many UK sites cap AEGs at around 350 fps on 0.20g BBs, so always chronograph the completed rifle and confirm your site's limit before play.

M4 Complete V2 Gearbox