Bill there is no gasket between eng/trans so it sounds like the rear seal.If
it gets on the clutch it will cause it to jerk and eventually slip in
gear...no smell..no warning.. or it may chatter when moving off line. You can
fix it by removing the tranny only and then flywheel.If the crack is merely
superficial,I wouldnt worry about it...unless it cracks all the way across.I
would follow the recommendation of a list member and stress relieve the crack
with stop drilling.At least it will not get any larger.Good luck.
Ed Berroth
84  Westy Wolf
87  Stinkcrow