[rdfeatherstone]

Question for the owner.

Does the pulley have a problem with runnout? What about the idler pulley, if installed?

If I detected runnout, I'd pull the pulley to mount it in a lathe and check the runnouts of the bore to the OD and the mounting face. If these are running true there is a possibility that the entire unit is "****ed" one direction or another with respect to the mounting "plane" of the engine's accessory belt pulleys. Either the pulley was mis-machined, or the mounting axis of the blower with respect to the plane of the accessory drive pulleys is the most likely cause of the belts dying early. One additional possibility comes to mind. The pulley on the blower is either too far forward or too far back with respect to the accessory drive plane.

Have you and your associates checked any of these possibilities during your troubleshooting process?

Let us know, as I at least, am curious as to the root cause.

Ralph