hmmm, interesting point. i was told mine has an uprated diff and that has a tendancy to give a sort of vibration/droning affect fron time to time.
ill get it on a ramp soon and have a look for markings as i forgot last time(and check the oil:chuckle
if i wasnt so useless id post some pics but i havent sussed it yet;bloody computers

. see if i can get some help maybe.
kev