[sammyg2]

Here's a possibility that will probably shock many on this board:
I have pulled several of these nuts off while at the junk yard, with a 1/2" breaker bar and no pipe.
I spray a good penetrating oil on them, remove the cotter pin, and use a rather large hammer and punch. I hit right on the edge of one of the castleated parts (sp) in the direction of loosening. About 10 good wacks should do it. Not hard enough to deform the nut completely, just enough to put a good flat spot on the part you are hitting. After that, they came off pretty easy. The shocks are enough to get the penetrant into the threads and lubricate everything. It is possible that doing this could damage the nut, and if you hit it really hard I suppose you could damage the rear wheel bearings too, but I didn't have to hit them that hard.
PS I did this on cars that were jacked up in the air, had no e-brake, and one didn't even have a transaxle in it anymore.

Just one more solution for when you get in a pinch....