Well I guess that's one way of supporting the other end of the arm. You may damage the long bolt though when you sledgehammer the arm. That's why I supported that end of the arm on an axle stand. That and the fact that I couldn't get a good swing with the sledgehammer with the arm in that position. Took about 5 hard bangs with the sledgehammer (and I mean a sledgehammer with a 4 foot handle) to get the balljoint out. That's after I'd spent an hour with pickle forks, air tools etc trying to bash the joint out from the top.