Play in Driveshaft on F650

[hunternielson]

Hi all,

I'm on the road, in Southern Tanzania, (just put the bike on a motorboat across the Rivuma River a few hours ago) on a long ride, and am experiencing a curious clunking sound coming from the area near my right ankle.

I found that the 32mm nut holding my sprocket on was loose not long ago...much to my dislike...and after tightening it I found that the clunking noise stopped. Then later, it started again, only this time the nut doesn't seem to be loose (at least I can't move it with my fingers this time) and I've noticed there is in-out play in the shaft the sprocket attaches to...

So, what's the clunking? Is there supposed to be play in the shaft (not more than a mm, very similar to the in-out play on the gear shift pedal...)?

I'll be around town fixing broken welds for a day or so.

Help!

Cheers,
Hunter