ASAT Special truss rod is a little bit more stiff than befor

[Propjob]

Have an 2002 ASAT Special US that I am setting up due to the NE weather. While getting ready to adjust the relief, I noticed rod is harder to turn. I was able to back off the rod and then move clockwise, but it does seem to be a little tighter in both directions. As this is the hex truss rod, is there any trick that you know of to lubricate? It is still adjustable, however looking to prevent any future problems. Was not noticeable before spring. Looked through the posts and on the net , but found nothing that helped.
PROP