I think it just fatigued .The 60' has been goin away and I think it has been flexing .The left lane was hooking good friday nite I noticed .It was cool sat morn and I had it on kill.The stevecraft bar has been damaged ,the levers were bent on the drivers side.Im glad I had the bar because it was the only thing holding the rear in place.I think if it wasnt their the body damage to the quarter panel would have been worse.The tire was tore up and the quarter panel was damaged.Im getting the rearend out now and goin to try to fit exhaust in their while it is out