I've also had to put axle in tripod stand chain vise. Soak the caps real good. Then I found a steel pin just smaller than cap. Then beat on it with small sledge hammer. Pain in the butt, but it worked.

 

broke one of my new u joint caps!!!!!! i just cant win i guess that is 60 bucks down the drain

 

here are some pics of my puller and the rust i was talking about. again the puller is a piece of 1/4 inch c channel with 2 notches cut out of the ends to fit on the lug nuts, and a nut welded to the middle that comes into contact with the axle shaft to give it the push off and the strongest bolt i could find.