Looks like it's my turn for some help. I removed my pitman arm and am now putting it back on. It's about a 1/4" short of being fully seated. I have a beast of an impact wrench. It's far enough away that I'm worried I'll strip the threads if I keep going at it. I'm wondering if it is the lock washer that is causing the issue? I saw a thread somewhere not long ago where someone was having the same issue.

I've got 99 problems and now my pitman arm is one....

 

Never mind. Brain malfunction. It was seated. I have a taller nut than stock which made it appear unseated.