He remained with the club through their greatest European successes in 1983 before moving on to become manager of Dundee FC in 1984. Archie returned to Pittodrie in 1986 to replace Willie Garner but when Fergie decided to join Manchester United in the Autumn of 1986 Knox announced that he too would make the move south. Not wishing to leave Aberdeen without managerial cover, Archie stayed on at Pittodrie for three matches, his last being a 5-0 victory over Clydebank under the eye of newly appointed replacement Boss Ian Porterfield.
Over the next 24 years Archie served as assistant manager at many clubs as well as with the Scottish National side, but late in 2010 he returned to Aberdeen to work alongside manager Craig Brown with whom he had shared duties at Motherwell in 2009/10.
Retired from Pittodrie duties along with Craig Brown late in season 2012/13 having played his part in steadying the ship and laying foundations for Derek McInnes' new regime.