Hi David
I had a large open ended spanner with a forked end in line rather than ofset at an angle, similar to the plumbers type that fits round a sink drain nut.
It had very slim ends and fitted on the lock nut just fine.
Unfortunately I dropped it and found it was made of cast iron.
You could probably make one from a bit of 1/4 inch plate steel.
Alternatively try knocking the lock nut loose with a cold chisel and then see if the collar comes off by hand. or pursuade with a chissel as well.
I little heat will probably loosen and soften any hardened grease.
Mike Edwards
Seal 28 "Aztec"
Mike Edwards
Seal 28 "Aztec"