Mine was regularly maintained and I blew the ring and pinion going down the highway on stock tires with a 4 banger. -- of course it had 185,000 miles on it,
I would have to say something went wrong...my 35 has 250k on it and it has a locker...ran several sets of 33's through it and now on 35's. This is all hooked to a fuel injected 383. Hell, it still has stock gears. Only thing I ever did to it was put a pinion seal in it after I got fishing line wrapped around the pinion. Change the fluid once...sometimes twice a year.