jurid coupling
No jurid coupling...known to me as a guibo. In any case vibrations typically are cuased by a notchy u-joints. Also check the center support. Basically you're gonna have to remove the shaft and perform a good inspection.
in rare cases... a balance weight can rust off or the shaft can be dinged or damaged in some other way.
in rare cases... a balance weight can rust off or the shaft can be dinged or damaged in some other way.






