Saturday, just drifting down the hill to my house, car idling along, the aluminum crank underdrive pulley broke at the keyway. It took out the crank bolt too, so now I have that to deal with. Of course the bolt didn't break off clean, it broke at an angle. Too deep to weld a anything on to remove it. I've had these on for over four years with no problems, in fact, it was the first mod I did to the car. The only bright points to this are, it broke within 100 feet from the house, so no overheating problems, and it dropped down instead of flying in any other direction like it could've, taking out the radiator or hood. That's why I'm not too mad (now) once I thought about it! Sure it's gonna cost, time and money, but it sure could've been ALOT worse! Just thought I'd share the agony.