Considering the condition of the transfer case we saw no need to analyse the oil...the shards did seem to be the result of bearing failure. The oil was VERY dark compared to new. Nevertheless, the TF0870 lubricant is not considered a permanent lubricant...and to replace it every 30-40K miles seems a reasonable measure. There is a documented procedure for replacing it and resetting the electronics. I plan to replace it in my 2008 at its next service. Electronic monitoring is fine, but as a Hardware Product Manager at a really big computer company...I can tell you they can't cover everything!