I haven't been paying a whole lot of attention to this thread, but I
think that John D. has summarized well all of the elements that have
led to the confusion. I understood Jim's original question to refer
to what was called "pole wandering" when I first heard about it years
ago. It was described then as a kind of "random walk" of the point
where the earths spin axis pierces the earth's surface, and it was
said to move a few meters every year but not in any neatly systematic
way--kind of like the wobble in a system where the angular momentum
vector and the angular velocity vector don't point in exactly the
same direction, like when tires are not dynamically balanced. A few
decades ago when I had the opportunity to visit the South Pole
(briefly--about an hour), I went over to where a pole stuck in the
ground supposedly marked the point, but was told that that location
was outdated--the pole was actually about 10 meters away from there
at the moment, but was moving enough that it wasn't worth their
effort to keep moving the marker to stay up with it.
I understood at the time that this "wandering" was due to the fact
that the earth's center of mss was not at its geometric center due to
uneven distribution of the mass in the earth's interior, and that its
motion appeared random because of all the other gravitational
influences (sun, moon and Jupiter, primarily), whose varying periods
relative to the earth provided perturbations that changed kind of
chaotically.
Is this the variation in rotational axis that you were talking about,
Jim? If not, I'll crawl back in my shell and shut up.