Yay! Uh, I mean, bummer that sucks!
Glad you got the seals, but sorry you ran into a very common EB box problem from way back. Maybe it's been cracked for awhile?
Back when everyone took theirs off roading, especially with larger tires and any type of traction aids, the stock boxes cracked cases and broke sector shafts on a fairly regular basis unless you were pretty easy on things (driving like you knew it could break in other words!) until the '76 and '77 box came around. I think the quicker steering ratio put less torque into the box and more into your hands maybe? But that's just a guess.
It's also the reason there are so many different boxes that have been tried on Broncos. Not to mention the cost of the stock ones having been through the roof for the better part of the last thirty years or so.%)
You going to go back with stock? Or beef it up some? Knowing how you will drive it and what size tires you have will help you make that decision, but if you're going to be playing hard with it, now's the time to upgrade.
Otherwise, nothing else wrong with stock, and lots of them still on the road to prove it.
Good luck.
Paul
;D but you'll make up for it in plumbing, fabbing, fiddling and farting I'm sure.
