Wiper spindle grub screw seized ... how to remove drum?

[towe0609]

On my 97 defender I have a lot of play between the drum (STC987 (https://www.google.com.au/imgres?imgurl=https%3A%2F%2Fwww.lrdirect.com%2Fima ges%2FT%2FSTC987.jpg&imgrefurl=https%3A%2F%2Fwww.lrdirect.com%2FSTC987-Wiper-Arm-Adaptor%2F&docid=j_P_r8wu7ypSWM&tbnid=19ptM00jsJ5GVM%3A&vet=10ahUKEwjo1oHiqI3VAhXHi7wKHefKCkMQMwgpKAQwBA.. i&w=300&h=300&bih=993&biw=1422&q=STC987&ved=0ahUKEwjo1oHiqI3VAhXHi7wKHefKCkMQMwgpKAQwBA&iact=mrc&uact=8)) and the spindle for the wiper arm.

After spraying with penetrating lubricant, I tried to remove the grub screw in the drum. Couldn't budge it, so I got a 1/4 bar and the right sized bit (3/32) and managed to break the bit off in the grub screw ... level with the head of the grub screw so I can't get a pair of pliars onto it either.

I need to replace the drum. The question is how best to remove the drum without damaging the wheel box assembly now that I cannot remover the grub screw?

Does the grub screw go into a slot, or just onto the flat face of the spindle?

Shall I take the angle grinder cutting disk and basically try to cut/grind the grub screw? I assume the drum should then slide off?

[strangy]

Try drill the grub screw out and either redrilll/ tap oversized or replace.

[Phil B]

The grub screw bites onto a flat on the shaft
If the adaptor is seized onto the shaft you may be better off cutting the shaft and replacing the wheel box
PITA because you have to take the top of the dashboard off. Advantage is you can refurbished the whole system while you are at it.

[JDNSW]

You may be able to get it off by heating the adapter with a heat gun, failing that, since you are replacing it anyway, careful use of a grinder, preferably a dremel or similar is indicated.

John