While it is good to do maintenance on your gearbox, I am a believer in not fixing items that aren't broken. Maybe you can go another season without touching that gb.
If you are interested in learning the job, then take it apart. If you are just concerned about maintenance, don't worry until you have 40 or 50 thousand shots through it. Then you can inspect it for wear.
My TM MP5K PDW had over 100, 000 cycles through it by the time I opened it up the first time. It was like new inside.