[JFP in PA]

OK, here is the part that is missing: For some time, it has been known that not all of the IMS shafts were created equal; some spin true, while others have shown significant run out, which causes the shaft to wobble and literally beat the Hell out of the bearings. I think Jake first picked up on this when he examined engines that had multiple IMS bearing failures. Others mistakenly identified the issue as a thrust problem with the ball bearing design, leading to the development of the roller bearing replacements, which in fact have no better load carrying capacity that the ceramic ball bearings, and do not in my opinion really offer any better performance in a high run out shaft.

Unfortunately, the only way to test the shaft for run out is to take it out of the engine and test it on the bench, making testing in the field a non starter. And this run out issue may factor in to why some dual rows fail, while other go on forever. All of this went into Jake's development of the IMS Solution, which is decidedly more tolerant to run out in the shaft than any other style bearings, and which should outlive the rest of the engine as well.