Rob wrote:

shane wrote:
Hi, I want to top the the oil up in a rear axle, as previously it was
leaking, but the filler plug is seized.
Someone has tried to remove it before slightly rounding the nut so that
now a socket will not fit.
I have brought some stillsons, but has anyone got any tips to make it
easier to get off without damaging the plug, for example would heating
the plug up first help?
Thanks
Shane

you could hit it with a hammer, end on to break/jar the seal. Is it a
parallel thread or taper?
I'm not sure, I think it's probably a parallel thread, thanks for the tip,
I may try that.