Description
ACM Polymer Piston with Full Metal Teeth (15 Teeth)
This ACM piston is a replacement piston for AEG gearboxes, with a polymer body and a full rack of metal teeth. The piston is the part the sector gear pulls back against the main spring on every shot, and the teeth take a great deal of punishment in the process. Original pistons with plastic teeth are one of the most common failure points in an electric gun, so a metal-toothed replacement is a sensible repair or upgrade.
ACM supplies affordable parts and accessories for a wide range of replicas. This piston suits players repairing a gearbox with stripped piston teeth, or anyone rebuilding a rifle and wanting a sturdier piston without going to a heavy all-metal design.
Build and design
A polymer body keeps the piston light, which helps the gearbox cycle quickly and puts less strain on the motor, while the metal rack spreads the load from the sector gear. This piston is listed with 15 teeth, all metal. Tooth count matters: it has to suit your sector gear and the way the gearbox is set up, so compare it with your existing piston before fitting.
Fitting
Fitting a piston means opening the gearbox. While it is apart, it is worth checking the piston head, cylinder head and nozzle for wear and making sure the piston slides freely in the cylinder. If you are new to gearbox work, ask an experienced technician to fit it and check the shimming and angle of engagement at the same time.
Key features
- Lightweight polymer body
- Full metal teeth
- 15 teeth
- Replacement for worn or stripped pistons
- Suits repairs and general rebuilds
- Affordable spare from ACM
Compatibility
Pistons are broadly interchangeable between many AEG gearboxes, but tooth count, length and piston head fit vary. Check that 15 teeth suits your gearbox and sector gear, that your piston head will fit, and that the piston matches your gearbox version before ordering. Heavy upgrade springs may call for a more robust piston.
Care and maintenance
Lightly grease the teeth and the rails the piston slides on, and keep grease off the piston head and cylinder walls where it can collect dirt. Check the first and last teeth for wear whenever the gearbox is open, and correct any angle of engagement problems to stop the teeth wearing early.
Who is it for?
A good-value choice for home techs and players repairing a gearbox after stripped piston teeth, or replacing a tired piston during a service.
