Aha part 247766 has come loose
Looking at the parts manual I now know what has come loose behind the
pulley, part 2447766 described as a "mud excluder" and held on by 8 screws,
all of which have obviosly come out.
It looks an awkward bugger to replace cos I can't see how to get at it
without removing the radiator to remove the pulley unless I had extremely
long arms and amazing agility.
I assume it is safe to run for the time being with this thing off, so long
as I am not going through any mud,
Series 3 rust and holes