I've never done a Caravan Axle, but usually, there is a bent over bit of the axle nut that nests in a slot in the axle stub. Did you pry this up?

There is no substitute for real tools. If you have a no-name impact, pitch it. I have an IR Titanium 1/2" and it has never failed me.

Finally, perhaps a 3/4 drive Harbor Freight breaker bar is what you need here. Check the torque spec's on these nuts, but other cars that I've done typically spec the torque at 300ft-lbs, so this is heavy duty work.

Astrobuf