Modify Modular Gear Set

Does this fit in a 8mm gearbox? Thanks i wanna buy it

no....

I want to know how to work on Gearboxes anyone can tell where I can learn?

watch this:
AK47 G&G Desmontaje Gearbox V3
and this:
How to install a MOSFET (first video by darkdante)

and you get a pretty standard way to take gearboxes down and reassemble

:25 epic fail

is someone crying the the background?

the pre-shimmed gear set is supposed to be smooth and quiet, but it doesn't sound impressively different from a low to middle "class" shimmed conventional gears, perhaps the motor is not properly set yet?

I agree the sound is not so good, it's seems to be a marui class motor, maybe the new version of the kit with a G&P motor will be good. In my XM177 wgc custom (G&P) after a good shimming, the sound was just awesome, I think with the kit it will be like that or better !

Hey man Can you point me in the right dircetion? I don't know anything about working on Gear Boxes, but I would like to learn so I can work on my own. Is there a book or a site?

no crap he just put the motor on, there is no way it will stay ajusted properly