ALthough 'clock drives' operate to track a telescope so that it keeps up with the diurnal rotation of the sky every 23h 56m 4s, they operate by having one or more gears and shafts coupled to the polar axis of the telescope, which is itself a shaft. Now, machining techniques being what they are, it is difficult to produce shafts and gears that have perfect geometries. To turn a shaft from rough stock on a lathe, the precision by which the shaft can be milled to a perfect concentric cylinder is probably not better than 1/1000 of an inch. This means that as the shaft rotates, any error in the surface will appear as a 'periodic' bump. This means that, ultimately, there will be various periodic tracking errors at the arc second level projected onto the sky as these bumps in the shafts and gear work are transmitted to the polar axis causing it to rotate slightly slow, and then slightly fast with periods that depend on just which shafts in the gear chain are out of whack.
I do not know what devices are available on the market to compensate for these mechanical, periodic tracking errors. The best thing to do is to contact manufacturers such as Meade or Celestron directly and ask them what they have.