The only way, I found, was to carefully cut the old poorly chuck off. Using a thin slitting disc on my trusty 5" angle grinder.
Firstly cutting off the outer sleeves, then removing the jaws then cutting downwards, so I could grip with an adjustable spanner.
I had to cut close to the thread to weaken the bind on one side but then it more or less fell off.
Doing it this way doesn't damage the brake or any other workings. You just need to cut a slither off at a time and be patient 😜
New chuck fitted with lock tight.
It took me a hour.
