Originally Posted by KayS
i wonder how many of us are flying around with similar crankshaft pitting, not knowing there is any.
besides splitting the crankcase... how to detect that? could surface pitting be seen as debis in the filter?
Since it is corrosion, I suspect oil samples would have shown some thrust bearing materials from erosion after the corrosion events. Also if it is significant wear, the axial movement of the crank (dial indicator) would measure the increased clearance.
One might also expect small shiny particles in the filter, but only an analysis would link it to a bearing. I don't know what the construction of the thrust bearings are, but suspect, lead/tin overlay, copper barrier layer and aluminum body and possibly a steel shell.
It would be odd to see corrosion isolated to just the thrust surfaces, I would expect to see evidence widely in the crankcase.
IMO, it is worth sending the crank for inspection as a minimum as pitting can greatly
reduce fatigue life, but certainly not
use it as-is. Why? Not because I know, but because I don't