newbie shift question

[Bengalitron]

hey i got my x a few days ago, and this is my first 4wd suv.i shifted it into 4wd going about 20 mph for the first time today. then i shifted it back to 2hi. as the manual told me to do so, i stopped and went in reverse to disengage the 'hubs'. but what happens now is that a rattling noise comes from the drive shift lever. is this normal or is something wrong with it? the noise occurs when im accelerating from low speds and only or a brief moment of time.