[quote=Edchris177]Dave, it should be turnable with even a pair of pliers. When you get to that size nut, (I think it is 5/8") the wrench is a good length, I can turn mine to the 3/8" deflection with only a couple of fingers. If the top nut is not turned up, you cannot deflect the beam, & it will get very hard to turn.
The only other reason would be grit on the threads, stripped threads, or a slight bend in the rod. It doesn't take much bend to prevent rotation of the nut. You can easily check for trueness by rolling the rod (sans nuts) across a smooth flat concrete floor, marble counter or glass table top. If the rod is bent at all it will make a clicking noise as it rolls.
If the bend is very slight, you may get away with running a thread chaser, or die over it. Use some auto transmission fluid or other oil as cutting fluid.
Slight bends can be straightened by turning two nuts just above the bend, placing that area in a vice, & very slow careful bending.<!-- editby --><em>Edited by Edchris177 on Jun 02, 2011 - 06:05 PM.</em><!-- end editby --> [/quote]
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