Yes it is this bold I did mention, what wrench is needed? Because I have metric here and it is inches from that time. In mine case a mix by the way, maynbe because the rover is build in belgium.A tab washer shown in picture, holds the nut to the steering box.
I did see your picture shows a exgra bold just next to the mention bold, t his is not the case in mine situation, I have just three bolds, two are removed but this one not yet. Maybe yours is a 2000 or 2200 version rover? Or older etc.