Well JCB you would think that wouldnt you ???
BUT its actually not a spun bearing ! LOL
What happened is if you look in the lower pictures of the flywheel end of the crank still sitting in the cradle you can actually see its bent just in at the bearing.
The process of self destruction was as follows:
1) Dual mass flywheel failed causing imbalance in the end of the crank.
2) Last main beaing began to wear excessively causing more imbalance and movement in end of crank.
3) Imbalance at high RPM caused crank flex leading to the flywheel/clutch assembly contacting the gearbox bellhousing.
4) Bellhousing contact "kinked" the end of the crankshaft (forces in excess of 1800 Nm acting upon the end of the crank)
5) Clutch was damaged and started to slip
6) Previous Owner took car to garage regarding the clutch issue and strange vibrations at certain RPM
7) Garage incorrectly renewed the flywheel which was found to be faulty and replaced the clutch but DID NOT check for damage to the crankshaft
8) Car ran not too bad for 6 months being driven normally but due to the now kinked crank the bearing wear in the last main bearing got worse and worse.
9) Eventually the main bearing nearest the flywheel failed completely due to the huge forces acting upon it through crank imbalance and the next in bearing began to wear.
10) The now huge amounts of crank movement damaged the new DMF and was allowing the assembly to wiggle about contacting parts of the gearbox bellhousing again whilst all the time wearing the end and second main bearings more and more to the point of complete destruction.
The bottom liine is that the bearings have lost their white metal coating and completely destoyed the already badly damaged crankshaft.
It really is amazing to think that this engine was actually running sweet below 5500 rpm with no nasty noises !!!!!
The bits of spring that you see are from the RMS which was also badly damaged due to the movement in the crankshaft.
Luckily the filter in the oil pump has done its job incredibly well and NO debris has entered the pump or been moved round the rest of the engine meaining that the engine is repairable due to catching this in time !
It does look like a spun bearing at first glance but you can tell its not due to a few things,
Firstly the crank is clearly bent at one end, theres no doubt about that ! theres 0.43mm of runout on it which is crazy !
Secondly the locating tabs on the bearing shells are all intact and not damaged indicatiing that the bearings have not spun in the cradle.
Thirdly the cradle is completely undamaged somehow and there are not any signs of damage to the cups which hold the bearing shells.
I have ordered a new crankshaft and a cradle with main bearings as a complete unit so hopefully when it arrives I can get this beast back together within the next week and begin enjoying my Boxster again as it was designed to be !
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