Clutch started slipping today.
Quick look underneath sees a drop of oil on the jiggle-pin on the housing.
So off with clutch cover. Expecting to find oil.
And indeed there was some in there. But more, errm, "interestingly"... when I rotated the engine by hand, I could hear a quiet, but very very wrong, grinding sound.
Which turned out to be the teeth on the flywheel just beginning to scrape on the bottom of the clutch housing.
So, the cause of the oil seal failure seems to be that the crankshaft has dropped at the clutch end. Which is, obviously, real bad Bruce.
I wonder how long it would have carried on running, and how big a bang it would have finally failed with, if the oil leak hadn't caused the clutch to slip and prompted an examination.
Out with the subframe tomorrow for a better look and a strip-down. But, clearly, it's going to be £ugly£. Only 600 miles on the engine, too. I must have c*cked-up the rebuild, somehow. Tomorrow we'll see how much is salvageable.
:-(