hi there?new to this.just pulled the flywheel to change main seal today and found it has been rubbing on the back of the case around where the main seal goes,dont know the history of this engine drives fine,just thought i would do the main seal whilst doing the clutch and found this.end play is .008 it is old i had it sitting for almost 10 years put in in last year fired up within 1min.been going ever since,had plenty of engines but never seen this before.any ideas why,thanks dale