[Ritchy]

well usually a crank seal would leak down the back of a flywheel, if the kv6 is the same as k4 though you need to locktight the flywheel bolts as the k4 has an opencrank basically, but youd see it leaking out the bottom of the gearbox if it was leaking,
hope you sort it soon, sort the hydraulics out before condeming seals ect, i wouldnt remove a gearbox for a crank seal unless it was actually leaking out the bottom