See, I’m of the opposite view. In my experience rear crank seals rarely leak. If it isn’t leaking or showing signs of leaking I leave them be.... the last few I’ve had to replace is where a customer has fitted one after replacing their own clutch and thought “while I’m in here I might as well replace the perfectly good rear crank seal”. And then the new seal leaks shortly after. it’s a funny old world.

... same as when I do a clutch on the 1200 models, if the crank seal is dry, I don’t touch it, but the seal I do replace is the balance shaft seal, which outnumbers rear crank seals leaking 20 to 1 on the 1200 models.