|
Data provided in the IMS class action suit indicated single row IMS bearings fail about 8% of the time whereas double row bearings fail 1% or less. Structural weakness is the best explanation for the difference in failure rates with all things being equal except the 1) the relative amount of contact surface areas of the balls and races of the two designs and 2) IIRC the thickness of the bearing support,
Even the dual row bearings, however, do fail so structural weakness cannot explain all failures. I believe compromised lubrication probably explains a lot of the rest and the 1% underlying rate. This phenomena happens when acids and particulates in engine oil causes bearing seal degradation that allows oil to mix with the bearing's grease. The combination lubricates very poorly and after some time the bearing fails.
|