Why? Is it like this:
Person 1: "OMG! Where are the gears?!"
Vince: "Airsoft guns have gears?!"
Person 1: "OMG! Where are the gears!?"
Vince: "Airsoft guns don't need gears to work, just some lovin'."
Person 1: "OMG! What did you do to this gun?! All the gears are broken, the motor is missing, and the rest of the internals are on fire!"
Vince: "Fire you say? Oh that's normal. Just fire away about a thousand shots and it should put itself out. The gears arn't broken, they're just a bit loose and not attached to anything. They come in all sorts of sizes and shapes! That's why there are so many ones that looked cracked and cut in half!"
Person 1: "What about the motor?"
Vince: "Uhh...there wasn't one in there at the time, you should really check into buying one. Here's one of mine, they only cost $50 more than the leading brand"
Person 1: "How much does the leading brand cost?"
Person 1: "What did you do to my gun? All the parts you put in are cheap knock offs of the good stuff!"
Vince: "They're the new kind of cheap plastic, far stronger and more durable than the normal colder metal parts!"
Person 1: "They're clear. Like see through clear."
Vince: "Just fire a thousand shots and it should turn opaque".
(Apologies if he's a great guy, and does good jobs on airsoft guns. Also my knowledge of gearbox internals is sketchy at best, maybe they are made out of clear plastic