Inside every AEG is a gearbox — and inside the gearbox is everything that actually fires the BB. Bushings, tappet plates, anti-reversal latches, gearbox shells — the small parts most players never think about until one breaks.

An airsoft gearbox is a metal box containing the spring, piston, cylinder, gears, motor connection, and trigger contacts that together drive each shot. It's the mechanical heart of every AEG. Three gearbox versions cover most UK airsoft: V2 for M4-pattern rifles (the most common), V3 for AK-pattern, V6 for Thompson-style and a few specific platforms. They share design principles but the parts aren't interchangeable.

Common gearbox parts here. Bushings or bearings that the gear shafts rotate on — usually 6mm, 7mm, 8mm, or 9mm diameter depending on the rifle, the high-stress wear point that determines gearbox life. Tappet plates that drive the nozzle forward to feed each BB — cracks and wear here cause feeding problems. Anti-reversal latches that prevent the gears from spinning backward when the trigger releases — failure causes piston pre-cocking issues. Gearbox shells (full or half) for rebuilds where the shell itself has cracked or been damaged.

Not in this collection but related: the moving parts that the gearbox houses live in their own collections — pistons, cylinders, springs, gears, motors, triggers, and MOSFETs. For the full list of upgrade and spare components, see All Spare Parts.

💡 Titan Forge tip: If your AEG is losing FPS or feeling sluggish, the most likely cause isn't a tired motor or weak spring — it's worn bushings letting the gears wobble out of alignment. 8mm steel or bearing bushings are usually a £15-20 upgrade that makes a noticeable difference to consistency. Worth checking before throwing money at bigger parts.