[thom4782]

Oil starvation does not explain why the IMS failure rate of a sealed single row IMS bearing is 7 percentage points higher than its dual row counterpart rate of nearly 1%. The more likely reason is that single row bearings are weaker than dual row ones and, as such, they cannot carry IMS dynamic and thrust loads as well. This reason also explains why IMS bearings last longer in cars that run at higher RPMs - the drive it like you stole it ones. BTW: replacing the OEM bearing with a ceramic one fixes the loading problem.

Oil starvation also does not explain the roughly 1% failure rate common to all sealed IMS bearings. The most likely reason all IMS bearings suffer this baseline failure rate is leaking seals compromise lubrication by allowing oil to mix with grease. The resulting mixture provides much less lubrication to ball bearing and race surfaces than grease alone or oil alone. This reason also explains why IMS bearings last longer in cars that lessen the chance of seal degradation by changing oil often. BTW: installing an unsealed bearing or removing the seal on a currently installed bearings cures the compromised oil problem.

Oil starvation may explain potentially different failure rates in unsealed IMS bearing cars that use different methods of delivering oil to bearing assemblies. But first, it’s important to know if the failure rates of the two methods are actually different. The answer will come only when many unsealed IMS bearing cars with different of maintenance and driving histories amass a reasonably high number of service miles - say at least 50,000 on average. Until then, people must rely on seller opinions and the track records of their products. Both sellers claim their products are great. The LN Retrofit has a track record of almost no failures over several years. DOF is just beginning to build its track record.

So grab a few drinks and some popcorn and sit back and watch the debate as it unfolds over the next few years. Eventually, real world experiences will settle the relative failure rate question among the competing lubrication methods for unsealed IMS bearings.