EPS IMS Bearing Upgrade Kit

[wogin]

I just put the EPS roller bearing in a month ago. After researching this issue to death I ended up deciding to put this particular bearing in based on the following:

1) Roller bearing has a higher radial of load capacity than a ball bearing. I read estimates that the failure rate of single row ball bearings is as high as 10% before 100k miles but that the double row bearings had failure rates closer to 1-2%. The dual row bearing has more balls to distribute the radio load. This results in lower cyclic contact stresses in the balls and the races. In fatigue failure, even small decreases in stresses can dramatically increase the average time to failure of a part. A roller bearing distributes its load along the line of contact rather than a point. This design feature means that roller bearings will see much lower cyclic stress levels than a ball bearing of the same form factor. I chose a roller bearing over dual row ball bearing because I believe the cyclic stress level will be lower in the roller bearing than in a dual row bearing.
2) In reviewing pictures of the of the Boxster‘s engine’s internals, and the support configuration for the intermediate shaft, I did not see any sources of significant thrust load on the shaft. Given the lack of thrust loading, I concluded that the EPS bearings thrust washers would probably be sufficient to manage a inertial thrust loads.
3) I called EPS and spoke with them, and although they have not sold as many Bearings as The alternative suppliers on the market, they have not had a single reported failure. On the other hand I have read about failures on ball bearing retrofits (and The manufacture simply blamed installation rather than Entertaining the possibility that they supplied a defective product..)
4) cost. The EPS bearing was cheaper than a ceramic ball bearing retrofit, and the manufacturer claims it will last the life of the engine. Contrast that to the ceramic ball bearing that costs more and should be replaced every 40k miles. If I had all the money in the world to throw at this problem I would buy the Journal bearing retrofit kit, but for me it was just crazy to drop $1.7k on a 10% chance my $6k engine would blow up.
4) the speed of the ims shaft is compatible with the rated speed of a roller bearing of this size.

Finally, if I had a dual row bearing already in my car from the factory... I probably would have just left it alone... 2% failure rate isn’t high enough to justify the expense and hassle of replacing the bearing.

Please excuse typos. I wrote this on my phone and dictated some of it to Siri... she doesn’t hear me well sometimes.

Not looking to debate what solution is best, just throwing out the reason I made the choice I did in case it helps others with this decision.