Original post by: analogcd ,
Most likely the cause is the bushing in the speedometer. This is the fitting one sees when speedometer cable is removed, looking into threaded mount at rear of cluster. Suggested resolve is: remove cluster, apply four to five drops of '''SAE 20''' oil (''sewing machine oil'', “3-in-1 Electric Motor Oil” or equivalent) to the rotating element. This is speedometer part with square recess into which speedometer cable mates.