I will try those steps next time I'm out Ken.
Can you explain or point out how you can tell that it may be a backlash issue from my graphs? What are the signs that make you think backlash? And if it is backlash is it worth tinkering with the worm gear meshing or belt tension to see if I can fix/ tighten it up that way ? I will wait till I've had a chance to at least run the guiding assistant and see if I can resolve any issues there before stripping the mount down (never pulled the mount apart before..)
Knowing what to look for with problems like that should help me resolve any issues in the future. (ie. I remember reading somewhere that if the graph is see-sawing up and down, that it's generally because of the seeing conditions, or trying to correct too often/ strongly).