R1200GS - slight shudder

[Dean de St Croix]

Been feeling this for a number of weeks and read a post about the same thing on adventure rider... does anyone have any experience with this.

Faint rear end vibration/shudder.

Mostly in 5th around 3-3500 rpm - it is most noticeable when downshifting with a slight clutch slip. If I shift quickly and precisely it almost disappears. But - it is getting slightly worse. Under power it is fine - nothing noticeable but normal engine. The clutch shows no sign of slipping at all. Fine under power but can be felt both up and down shifting - slightly masked by engine in the upshift. I can also feel it in all the gears depending on load but varies with the gear.

Comments; R1200GS ADV 2006 - 12,000km light travel
1 - more significant in the higher gears - makes sense when it is under the most load - but that is contradicted by the fact that it is a light load situation - clutch slipping - downshifting.

This leads me to believe it is not the clutch but the final drive - with something loose in there.

2 - clutch is dry (of course) and no smell of burning oil coming out of it - or normal clutch burn

This tells me that it is not a slipping clutch as well and as I feel no slipping etc. it is hard for me to think that any adjustment on the clutch side would not affect the entire range of clutch action - so bleeding the clutch would not affect this. But - as someone has pointed out - it seems to work.

3 - When I pull the clutch in it goes away - but that means that there is absolutely no load on the drive train also - which points to drive train.

4 - rear wheel is tight with no movement - spinning wheel in gear or neutral is fine as well - nothing abnormal.

5 - I can consistently make this happen when I want - it is not random.

I don't know what it is... but want to figure it out before it is off warranty - it all points to something slightly loose - no clutch slipping to me means it is not the clutch - it could be a loose clutch housing or movement there though. It also might be some looseness in the final drive gears as that would show up now under light power as it is not under load - when everything tightens up.

Does anyone else have an opinion? It seems like this might just be a common issue.

Dean