Description
Bolt Gear Box Shell (M4GB05)
This is a replacement gearbox shell from Bolt Airsoft, part code M4GB05. The gearbox shell is the housing that holds all the internal parts of an AEG gearbox: gears, piston, cylinder, spring, tappet plate and trigger assembly. The part code points to Bolt’s M4 series, but check the product photos and your replica’s model before ordering.
Bolt is a Taiwanese manufacturer known for its realistic recoil AEGs, which use Bolt-specific internals. That makes a Bolt-made shell the safest choice when rebuilding a Bolt gearbox, because generic shells may not accept Bolt’s own parts. It suits owners repairing a cracked or worn gearbox and techs servicing Bolt rifles.
Why replace the shell
If a shell cracks, usually near the front of the cylinder area or around the bushing seats, the gears and cylinder lose their alignment. That leads to poor gear mesh, noise, lost power and eventually serious damage. Rebuilding on a new shell restores the correct geometry so your internals can work properly.
Rebuilding
Moving to a new shell is a full gearbox rebuild. Strip the old gearbox, clean and inspect each part, transfer everything to the new shell, set the shimming and check the air seal before closing. Bolt gearboxes include parts that are specific to the brand, so take photos as you strip it and follow Bolt’s layout. If you are not confident, ask a tech.
Key features
- Replacement gearbox shell from Bolt Airsoft
- Part code M4GB05
- Restores correct gear and cylinder alignment
- Ideal for repairing cracked or worn shells
- Designed to accept Bolt internals
Compatibility
For Bolt AEGs; the code suggests Bolt M4 series. Bolt gearboxes differ from standard designs, so do not assume generic parts will fit, and check your replica model and compare with the product photos before ordering.
Care and maintenance
Keep the gearbox clean during rebuilds and use suitable grease sparingly. Shim carefully, as poor shimming is the main cause of gearbox wear. Use a battery suited to your setup and store batteries outside the replica.
Who is it for?
Ideal for Bolt AEG owners with a cracked or worn gearbox, and for techs who need a correct replacement shell for a Bolt rebuild.
Please note: Supplied as the gearbox shell only; internals, motor and electronics are not included. Wear eye protection when working on springs.
