AEG's will just wear out - nowt you can do about that
G&G's bronzey bushings will go in aprox 12 months of regular use - depends on use and how much you cane it
Bearings will never last in tweaked guns - unless you use ceramic's and even then a solid bushing under spur is still advise I'm lead to think
Bushings will last longer but will still wear and also along with bushing/bearing wear the gear's shafts will wear also over time
You may get longer life depending on a number of things - type of bushings, grease used, how much you cane it and deffo how well it is shimmed/assembled
But it will just wear - if it is still going strong after many years - you ain't using it much or putting that many rounds through her imho
(or extremely fortunate)
This is all fine and to be expected - by then ya spring has dropped, ya o-ring on piston is probably knackered
so really it will need a service or partial rebuild anyway in say 12months of regular use maybe 2yrs but I haven't got a crystal ball
you should know ya gun and if she is sounding or performing a bit below par then expect it need investigating
(it ain't like fine wine and improve as it gets older so to speak)
months or bb's put through her.....
could be 12/24 months or 50k/100k of bb's
more if left stock - less if going nutz
Everything inside your gun is constantly wearing out from moment you assemble it it is wearing out....
The plastic tappet rubbing against metal tension by a spring - even if you got a bearing on sector that poor tappet is wearing...
The piston's o-ring when it dries a bit will start wearing very quickly
The spring is losing its tension as it thuds away - more if left pre-cocked
gears/bushings already mentioned those and metal on metal gears is nothing compared to extreme stress the bushing/bearing behind sput is under
smack bang in the middle of bevel-pinion and spring-sector - this is the bastid that wears and cause such failures taking out teeth quicker than any team of rip off dental surgeons could ever imagine....
As long as shell is ok, not cracked, bushings haven't worn the seating oval in box then most stuff isn't really that bad
At this point - this is where the owner could consider their options inside the box
The motor can be changed but these also have a limited life before at least one new set of brushes will be needed
(on a budget - you did keep that old crappy ferrite motor - just in case)
But again motors will die - if you wished you can grind the com but tbh most stuff is easier and less time consuming to just replace at some point
Then again - if gun really craps out - there comes a time where you either get it fixed or move on keeping/selling old faithful for parts etc....
But even brand spanking new mofo gun is starting to wear the moment you pull the trigger....
and so the toy gun risk of failures starts again..........
They will all crap out in the end - might last longer if lucky or assembled/serviced as best as possible but they will crap out in the end
Mount them on a wall, don't use them much but eventually they will crap out - heck some older ones have had the pot metal just crumble away over time
(though think this has a lot to do with how/where they are stored)
End of the day.... So what, service it when it needs and try to make it as good if not better
If the ar$e falls out and it is boned - buy a better gun - at least you had something to compare it to
If it fails - find out why and learn from it, if it don't fail (yet), leave it alone and enjoy it while it lasts
keep shooting - one day you will be the guy with a busted gun so whilst it works keep going