Notchy Drivetrain?

[Zig's GS]

If I turn the rear wheel slowly by hand while the bike (850 Shafty) is on the centre stand, there is a slighty notchiness (resistance) on 4 places (quarters). Is this normal or is the driveshaft coupling asking to be renewed?

[49er]

The universal joint that couples the shaft to the transmission may be on the way out. If so, you should have noticed a vibration through the frame. In the early stages quite minor, but worse as the wear and/or road speed increases.

If you hadn't mentioned feeling the play in 4 quarter rotations, I would have suggested you check out the drive spines at the diff. They wear out quickly when regular lubrication is overlooked.