Nikkor 50mm f1.4 LTM question

I just received a Nikkor 50 mm f1.4 LTM lens and there seems to be some rotational play between the back section of the lens that focuses and the front section of the lens (with the f stops) -- say 1/16". Another way of saying it -- If the lens is mounted in the body and the focus is locked at infinity the "." and the f/stop dial has some play. The f stop and focus isn't changing but the front 1/3 of the lens rotating slightly. Is this normal, some weird Nikkor thing, or is something loose that should be attended to? Hope I am explaining this clearly.

No, it isn't normal. Bring it to service, where are some which take care of old metal and glass lenses. Sometimes it is as simple as re-tightening correct ring or screw, but experience needed to be able to get to this part which needs to be re-tighten.