Anyone ever dealt with the bolts that are used on the axle flange to the rear hub on a 70/80 rear?

I put my truck back together this weekend and when i was putting the axle bolts back in I used an impact gun turned down on low, just to run the bolts in snug. Well apparently these bolts were from a bad batch or something because 2 of them snapped off. after extracting the bolts and replacing them with some non-grade 8 hardware i had in the garage, I ran the rest of them in by hand.

Got the torque wrench out and went to tq them at 90ft-lbs like the manual calls for. First bolt snaps off before it ever got to 90. I gave up, used a short handled rachet to get them tight, but no torquing.

 

they are probably seriously fatigued. All the torque of your motor is transferred through those bolts.....

 

yup............

 

well i will be getting 16 new grade 8 bolts this week, I guess there is alot of stress put on them.