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Old 10-22-2013, 05:06 AM   #83
thom4782
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Join Date: Sep 2010
Location: Foster City CA
Posts: 1,099
The decision to reduce IMSB risk with what technology would be an easy one in a world of perfect information. That world doesn't exist for the Boxster community today and will not exist for years to come if ever. Owners can only rely today on the available empirical information and the opinions of the developers and other community members.

My calculus is simple...

1. The differential IMSB bearing failure rates documented in the class action law suit make it more likely than not that single row bearing weakness is the root cause of the majority of IMSB failures.

2. The LN Retrofit dual row real world experience over many years and thousands of miles make it more likely than not that it is a life of the engine fix as Charles opines.

3. The LN Retrofit single row experience suggests it is a long term fix, at least 50,000 miles, but its developers caution about inherent single row bearing weakness suggests it is a wear item that one should consider replacing at the 50,000 mile mark.

4. DOF may extend the worry free lifetimes of single row ceramic bearings far beyond wear intervals, but there is no empirical experience or developer opinion to suggest by how much.

For me, the above is more than enough to make an informed decision regarding how to mitigate risk. I don't find further hypotheses about possible failure mechanisms or the merits of one technology versus another helpful. They are speculative and their degree of correctness is unknowable without more data. And that's the beauty and curse of the scientific method - hypotheses are just informed guesses that beg confirmation through laboratory or real world observations before they are proved correct or not.

At the end of the day, each owner must look at the data, opinions and speculations that lie before him or her and decide for themselves if, when and how to deal with the IMSB risk problem.
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