I am glad people found the paper interesting. Yes, it is an interesting thread.

Lubehead: with a user name like that, you should give us some of your background; I suspect it is relevant to the discussion.

ard: I knew you would like the maxims at the end of the article. Yes, different stakeholders have different objectives. In reference to BMW's objectives, overall I think they likely parallel ZF's in providing maintenance recommendations: neither wants their good name besmirched. They both have a brand to protect. I don't subscribe to the hype around marketing driven reductions in prepaid maintenance costs, as I see little public pressure on those maintenance costs. In reference to the paper, I would be interested in your thoughts on maxim #4 (most failures are not more likely to occur as equipment gets older) and maxim #7 (the frequency of condition-based maintenance tasks should be based on the failure develoment period, or lead time to failure). These two points do not support following a preset fluid change interval in the hope that it will reduce transmission failure rates. They do support monitoring the fluid condition; my question then is what the criteria will be for flagging a problem fluid (apart from the obvious, such as water contamination). I don't believe we have specs for the friction modifiers in the fluid, which are being depleted over time. We could certainly measure viscosity, and trend it.

Jeff

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