And just in case you haven't realized it yet, the gearbox is what makes the gun work in the first place (actually the battery makes it work, but you won't get it to shoot without a gearbox). Seriously, unless you have the time and inclination to work on a broken gun, I'd wait until you had the right amount of cash and invest in an operational unit. In addition, buying someone elses trouble is never a wise choice. I'm sorry, I don't mean to sound like a sage, it's just that alot of us have been 'there' and have sad tales to tell.