If unsure, check out go-mog workshop manual online: “Front Suspension” section, click on paragraph 12.03 headed “crossframe adjustment” and you will see a diagram in which they refer to it as a crossframe stay.
+1 for the issue being a broken diagonal stay as shown below from GoMog article.
ETA: Note when car is jacked up to investigate the load removed from suspension may leave this stay in slight compression so a break may not be immediately obvious.
Last edited by RichardV6; 23/05/2107:16 AM.
Richard
2018 Roadster 3.7 1966 Land Rover S2a 88 2024 Royal Enfield Guerrilla 450 1945 Guzzi Airone