JG Full Metal V2 Rear Wired AEG Gearbox

If you've split a gearbox shell, burned out a piston, or just want better internals than the budget gun you're running, you need a complete replacement that fits without hunting for a dozen separate parts. The JG Full Metal Version 2 gearbox is that replacement for M4/M16-platform AEGs. It's a drop-in V2 shell with metal construction throughout, which is the most widely supported gearbox type in airsoft and the one you'll find in everything from Tokyo Marui to CYMA to Krytac builds.

Why the V2 matters. Version 2 is the industry standard shell for M4, M16, MP5, and G3 platforms. That means gears, pistons, springs, cylinders, and even entire replacement shells are off-the-shelf. If you need to tune velocity, swap in a different gear set, or upgrade the hop-up, every part you'd want is available from multiple manufacturers. You're not locked into a proprietary ecosystem.

Full metal over polymer. The shell and internal components are metal alloy rather than the polymer found on entry-level gearboxes. Metal handles the stress of heavier springs better and resists cracking around the cylinder window and trigger area — the two failure points that kill budget shells. This is the upgrade path when you're ready to move beyond the gun it came in.

Rear-wired design. The motor wiring exits from the rear of the gearbox, which is the traditional configuration. This works fine in most AEGs, but if you're installing into a stock with a tight buffer tube or a folding mechanism, you may need to route the wire carefully or consider a front-wired variant depending on your platform.

Not LiPO-ready. This gearbox does not include a MOSFET. Running a LiPO battery (7.4V or 11.1V) through a non-MOSFET gearbox can burn out the trigger contacts due to high current draw. It will run 8.4V or 9.6V NiMH safely, but if you want to use LiPO, you'll need to install a separate MOSFET or upgrade to a pre-wired unit.

What you get. This is a complete gearbox — it ships with the shell, gears, piston, spring, cylinder, motor mount, and all internal components assembled. You'll still need to source your own motor, hop-up unit, inner barrel, and externals to build a complete rifle, or use it as a direct replacement in an existing platform.

Compatibility. Fits Tokyo Marui, JG, and compatible SIG series AEG rifles. If you're unsure whether your platform uses a V2 shell, check your current gearbox — M4/M16-style rifles almost always do. AK platforms use V3, P90 uses V6, and M14 uses V7 — this won't fit those.