So I've got the MINI all blown apart in the midst of a TSW spring install I'm trying to get done today before autocross tomorrow morning, and I've hit a snag: How in the hell do I get the damn top nuts off the strut??? The freakin' strut shaft just rotates! Short of a special socket that would allow me to get at the allen key and the nut simultaniously, is the only other answer an impact wrench (and woulden't the shaft still spin?)? I've got one, but it (or more likely my compressor) is so crappy that I can actually do better with bare fingers... So I don't think that will work...

 

Ok, wow... I kinda figured that thing would be torqued on there like a mother, but I guess not... I just held the upper spring perch in place with a vice-grip and had at it with a breaker bar. Came right off.

Wow. Total n00bage right here.

 

Sometimes that works... sometimes it doesn't... fortunately, you got lucky.

The most common methods for removing this nut are either an impact wrench (the repetitive "hits" reduce the amount the shaft rotates) or a special socket - either purchased or home-made. I have a home-made version: A socket with "flats" ground on the side to allow griping with a cresent wrench while holding the shafter with an hex wrench through the drive opening. The purpose made socket looks similar to an O2 sensor socket, only a bit thinner walls and allows turning with a ratchet while holding the shaft with a std hex wrench through a window-opening in the side of the socket. A common vendor is ZDMak tools:

 

Another option is to use a spark plug socket.

You should never rotate the strut shaft, it will damage the strut.