banging/knocking/creaking transmission?

[fredT]

After sitting on the motorway for quite a while I came off and came to a stop more or less in a straight line. When pulling away whilst turning right there was a banging sort of sound almost sounding like a chain jumping on a chain wheel/ sprocket.
It doesn't happen under any other condition, only after coming to a stop after sitting on the motorway. Turning away left or right doesn't matter and it doesn't happen every time.

Any Ideas?

Thanks