CHAINCASE RUBBING ON S/ARM

Hi All, removed my pri c/case today as theere is a hairline crack around the front m/ting bolt (850 mk 2a) & noticed that the s/arm is rubbing lightly on the back of the chaincase, is this normal?
It has adj iso's & is set to 1/4 turn back from zero & there is no play in s/arm brgs. There is a spacer/washer on the mtg stud behind the 'case, the gap was measured after the case was fitted so I know that is ok.

Thanks for your help, Paul.

No, the inner chaincase should not rub on the swing arm. It could be various things. Incorrect or missing washer at top left side under the gearbox top bolt. Loose or oversized holes in the engine for the mounting studs, oversize holes in cradle for engine mounting studs, inner cover shimmed or mounted wrong. I have about 3/16" clearance there on my early bike.

Dave
69S