I had a strange problem with the bolts that mount the head to the shank too. The spec for them is 150 ft lbs + 1/4 turn. I must have moved the head 10x in the last two weeks. On my last move I got about one turn in when removing the nut and it was STUCK. I don't have a 3/4" socket and I gave it all I could with the 1/2" socket, including a good quality 1/2" impact gun. Eventually I had to cut it off.
Originally I cut one entire face of the nut off and it still wouldn't turn - as if it was welded on. I had to cut through then entire bolt to get it off. It was not cross threaded. I guess it's possible a small piece of metal got in there but it went on without incident.
I was thinking that the 150 ft lbs + 1/4 turn messed up the threads enough to cause some kind of failure that seized up the the nut when trying to take it off. My effort to remove with a 3' breaker probably didn't help either.
There are new bolts and nuts on there now.....
The same thing happened to me. I think it was caused by having grade 8 bolts and common nuts and washers not able to withstand the 450 ft-lbs torque. I emailed the Equal-i-zer company about this and never heard back.
