When I removed the rear axle from my GLHS, one of the bolts broke off flush with the frame. I tried welding a nut to it twice to remove it, and both times I broke the welds before I got the bolt loose. So I spent tonight drilling. So just in case I can't save the threads, has anyone ever had to replace the nut inside the frame rail? It seems to be an extruded nut that is spot welded inside, and I'm looking for tips and suggestions before I attempt to drill the whole thing out and fish a new nut in there.