Confirm the exact product
Read the product description and selected variant. Compare tooth count, shaft dimensions, gear type, listed gearbox versions, and any installation notes.
GEARBOX GUIDE
Airsoft Gearbox Compatibility Guide
Identify common gearbox families and verify the shell, gear geometry, tooth count, bushings or bearings, electronics, and surrounding components before ordering.
START WITH THE PLATFORM
Gearbox names do not guarantee component fit
V2, V3, SR25, and SVD are useful platform labels, but manufacturers can use different shell dimensions, bearings or bushings, trigger systems, cylinder layouts, tappet components, and internal clearances.
Inspect the surrounding system
A gear can match the general platform but conflict with the piston rack, shell, bearings, ETU, cutoff lever, tappet timing, motor position, or another internal part.
COMMON GEARBOX FAMILIES
Platform comparison
Use these rows to identify the likely gearbox family, then complete the fitment checklist below.
OptionV2
Best suited to
Common in M4, M16, MP5, G3, and related AEG layouts.
System pairing
Typical long-motor arrangement with V2-specific shell, trigger, selector, tappet, and wiring layouts.
Check before use
Verify shell brand, bearing or bushing diameter, trigger or ETU clearance, gear shafts, and nozzle system.
OptionV3
Best suited to
Common in AK, G36, AUG, and other V3-based AEG platforms.
System pairing
Different motor cage, trigger arrangement, selector system, and shell shape from V2.
Check before use
Do not assume a V2-labeled internal part fits V3 unless the manufacturer lists both.
OptionSR25 / V2.5
Best suited to
Extended-cylinder builds and platform-specific SR25 gearbox designs.
System pairing
May use a 19-tooth piston and sector gear, longer cylinder, and different shell geometry.
Check before use
Confirm tooth count, cylinder length, piston rack, shell version, and exact gear-set specification.
OptionSVD
Best suited to
SVD-series AEGs with platform-specific drivetrain and compression layouts.
System pairing
Requires parts specifically designed for the exact SVD gearbox version.
Check before use
Check every listed dimension and application; do not substitute a standard V2 or V3 gear set by appearance.
OptionDSG
Best suited to
Advanced dual-sector-gear builds for compatible gearboxes.
System pairing
DSG describes the gear cycle, not a universal shell version; tappet, piston, spring, motor, and electronics must match.
Check before use
Confirm sector engagement, release timing, piston teeth, shell clearance, and safe technician setup.
BEFORE YOU ORDER
Airsoft part fitment checklist
Record these details before treating any part as compatible.
Identify
Gearbox version, shell manufacturer, AEG model, existing gear type, tooth count, and cylinder layout.
Measure
Bearing or bushing diameter, shaft and axle dimensions, available shell clearance, and any unusual spacing.
Cross-check
Piston rack, tappet plate, nozzle, cutoff or ETU, motor and pinion, selected variant, and product installation notes.
COMMON QUESTIONS
Airsoft gearbox compatibility FAQ
General guidance for V2, V3, SR25, SVD, and DSG fitment questions.
Will every gear set fit both V2 and V3 gearboxes?
No. Some gear sets are designed for both families, but the exact product must list the application. Shell dimensions, bearings or bushings, trigger systems, tappet parts, and internal clearance can still affect fit.
Are SR25 gearboxes the same as standard V2 gearboxes?
Many SR25 designs use an extended gearbox and compression system often described as V2.5. Tooth count, cylinder length, piston rack, and shell geometry can differ, so standard V2 compatibility should not be assumed.
Is DSG a gearbox version?
No. DSG refers to a dual-sector-gear cycle. It can be built in compatible gearbox shells, but it requires a carefully matched piston, tappet timing, spring, motor, electronics, and gear layout.
What photos help with a compatibility check?
Useful images include the complete gearbox shell, both sides of the open shell, existing gears, bearings or bushings, trigger or ETU, piston rack, tappet and nozzle, motor cage or grip, and any markings on the original parts.
