I ride a 2010 K1300S and recently I (think) I started to hear an abnormal sound from the power transmission along with increasing vibrations, it might have been there more or less all four years I've owned the bike but just recently caught my attention. The only odd thing I located so far is if I put the bike in (any) gear with engine off, hold the clutch handle and roll the bike forwards and backwards I can hear a clear clunk for every change of direction that seems to come from the gearbox / propshaft entry area, like there is to much play in some of the transmission components. In neutral there is no clunk. Is this normal for every K1300 or should I be worried? The bike has about 4000km on the clock, all services done according to schedule.