I'm not sure what caused it right now. I'll know more when I lock the cams down, remove the belts, and then remove the crank gears. Then I'll be able to see much more. The crankshaft is smooth, so no marks or nicks occured from that. But I've now heard the the seal inner diameter rubber lip should be "biased" inwards towards the motor, and not herniated outward. Does this make sense? THIS IS ONLY CONJECTURE at this time, I will post the facts when I have them. I was very careful when installing it last time, but must have missed some small detail. I'll let everyone know when I have more concrete information. Maybe I can spare some other poor soul from going through this.