Shock Linkage Maintenance        

It could be your shock, but it's more likely to be your shock linkage. It can be fixed in under an hour with basic tools, without removing the swingarm or shock.
This article gives a foolproof, step-by-step guide to inspecting, diagnosing & greasing the relentlessly abused bearings in your bike’s swingarm linkage.
Courtesy of Transmoto Magazine.