Metal Shavings Behind LN IMS Bearing - Need Advice!

[cnavarro]

It sure looks like there was a prior failure and there is contamination from the original failed bearing. The bearing looks very clean on the open end that is exposed to the engine oil and sump. If there was a problem with the bearing itself, I would expect to see some kind of contamination here as well. Is the bearing actually magnetized or is the debris pattern just appear to be that way?

That bearing is likely one of ours and is probably a kit we built in late 2009 or early 2010. I would be interested in getting that bearing back to have the manufacturer inspect it since they'll be able to give us a detailed report for that bearing and verify it is indeed one of ours since we have used JAF and other manufacturers for races in the past. We switched to IJK over for years ago according to the manufacturer.

All LN bearings have always had a seal on the back side of the bearing that faces the IMS tube to limit oil intrusion into the IMS, but not stop it. It's not possible to prevent oil from getting by the seal completely.

JAF is a well respected Japanese brand. Our supplier use their races and cages. Then the bearings are assembled for us with Japanese or US-sourced ceramic balls. Currently we use both SKF and Cerbec balls, both USA made. Timken / Fafnir make ceramic hybrid bearings, but not the balls themselves as they buy their balls from Cerbec as well. Everything is measured and every bearing is blueprinted. LN bearings don't just come off a shelf somewhere and get re-labeled. We use the best bearing guy in the industry for ceramics. If you go to a Motion Industries and try to order an ultra high end ceramic hybrid bearing, all roads lead to him. We have always from day one used the same source and went to him because of his reputation and quality.