I won't lie, I laughed. Could you elaborate on your question? It is too short and needs further scope.
this probably means you have a worn cam shaft or cam shaft or the arm that hits the cam shaft to open the valve is worn. this is internal on the engine.
most likely worn output shaft bushing worn
It could be as simple as a slight imperfection in one of the gears or it could be an indication that the drive shaft or "half shaft" is worn.
It could be from worn bearings on the shaft that the pulley turns.
micrometer
you need a tachometer
on the blower most bearings are flange mount, and will have a Allen set screw locking the shaft to the bearing,
Worn yoke/tailshaft bushing
replace worn steering parts rebuild steering shaft
leakage will happen and the seal will be worn in a short time after installation.
The under cut of a shaft occurs when the external surface of the shaft (mostly inside a housing, such a bearing) gets sheared or worn out. This reduces the outer diameter of the shaft in the enclosed region, leading to wobbling and further damage. More information here:- http://www.maintenanceresources.com/referencelibrary/bearings/rbshf.htm
Blower shaft bushing worn.