Removing rear pinion yolk nut...broke my breaker bar?

[72timemachine]

At the bone yard I was trying to remove that 1 5/16" nut off the rear differential yolk with a 6 point impact socket and my 1/2 break bar.

Laying on the ground with my feet against the p/s leaf springs of this 86 c3500 dually, I ended up breaking my American made breaker bar.

My eyes are not the best but is that factory nut slightly crushed so it will not come loose as are other factory nuts?

I cannot even believe how tight that was, I thought I was going to rotate the truck I was pulling so hard.

So what's next? I see guys on Youtube using impact guns but does this not cause the pinion gear and ring gear to chatter on each other and cause surface damage to both? I doubt an impact gun could get this nut off anyway.

Any help would be nice....thanks ahead of time.