These photos show the results of a teardown of the horizontal spindle of my Deckel FP2NC milling machine.  The machine was making intermittent squealing sounds, and getting worse with time.  The quill started sticking in the head, most likely due to thermal expansion from bearing heat.  I traced the problem to a thrust race that was spinning in the quill housing.  Fortunately, the needle race surfaces, which are integral with the spindle and quill housing, are fine.  I need to look at the thrust races under magnification to see whether they need replacing.  You can learn more about the problem and diagnosis on www.PracticalMachinist.com  in the Deckel forum.