IMO, you're not going to bend the axle on a 1/2 ton truck. Even if it did deflect a bit, you won't exceed the elastic limit of the steel.
There's a story in here.
I've bent the axle on a Ford Model AA when we got it stuck in the mud when I was a kid. But of course, we tied the
chain to the center of the axle, and my buddy used the back up and jerk method, then kept yelling at me to turn the wheels straight. I looked out the left side and the wheel was straight, but he was looking out the right side mirror at the wheel that was toed-in about 30 degrees. We both got out and discovered the center of the axle was about a foot closer to the front of the truck than it should have been.
Another story while I'm at at (sorry). I had a flat on the rear of my F250, and pulled into a WalMart shop to get it fixed. I stood there and watched the jack monkey try and jack it up from the pumpkin while it was loaded at max GVW with a camper. I told him to jack it at the spring mounts, so he tried to reach up to the front spring mount at the frame - way higher than his jack would reach.
AT that point, I drove it out of the shop.
