TwoOsix, you said that the engineer had replaced the oil checkvalve clamp with a smaller type. This clamp is normally an un-cushioned clamp which is realitivly loose fitting. I am not certain if this is possible but if a smaller clamp was intalled on the checkvalve perhaps the pinching force would be great enough to cause the valve to stick. The subseqent oil starvation would then cause the #8 bearing to fail. You also mentioned that the O/H shop replaced the checkvalve, did they say why?