Like many members of this forum, the clutch release bearing of my R50 Mini Cooper failed after a relatively short life of only 51387 miles back in March. In what I hope is a unique situation, the crankshaft was found to be excessively worn during the clutch replacement work. Despite having a full MINI approved Dealer service history and an Inspection II carried out as recently as October 2009, BMW Customer Services have paid no interest to the technical implications of this failure because I had the repair work carried out at an independent garage.
As crankshaft play is NOT a checklist item for any of the MINI Service or Inspection activities, this latent wear has occured over a considereable time, and is likely to have been out of specification for many years, perhaps even while the car was still within it's warranty period (axial crankshaft play service limit is 0.3mm, I had many mm of play!)
The pictures below are from actual the crankshaft and thrust bearings removed from my car.
As BMW's Customer Service advisors have been unwaivering from their policy of only considering technical inputs from Approved MINI Dealers, may I suggest that you ask for the axial play of your crankshafts to be checked at the next service; particularly if you have previously had issues with your gearbox or clutch.
Not exactly the "intrinsic quality of the marque" we would hope for from BMW!
Unworn Crankshaft thrust bearing surface:
The good and the bad:
Completely destroyed thrust bearing surface:
Thrust Bearing shell - the good side:
and the bad!
As the crankshaft replacement kit was £580 (GBP) and BMW charge 17 std hours to replace this item, this could be a non-economic repair for some cars!
I'd appreciate any feedback from other members who may have heard of or experienced such extreme engine wear: as I could not find any posts relating to crankshaft wear.
Additional images are in the galleries section under "ICE & Technical Photos" MINI Galleries - Cooper - S - One - Diesel - Works - Cabrio - R50 Crankshaft Wear @ ~51k miles