[Tom Goldman]

I tried one on my car when I had a micro v belt system on the car.
Two of them failed ,altho they were OEM units. ... locked up the overunning clutch.
may have been the rpm range , as I was running a small engine at the time and hitting about 8400 in the traps.
The most common application of these pulleys is on diesels ,to help minimize belt screech at shut down. ...They also cut down on belt whip when a automatic tensioner is employed .