Ko Chu was a big help to me as I performed CLA on my Canon 400mm f/4.5 nFD lens. After removing the drop-in filter, I slipped the focus ring rubber downward until it was about 90% off the focus ring. This exposed the 3 set (grub) screws and once I loosened them I could easily unscrew the front lens assembly. Then I could remove one screw that secured an "idler" to the moving rear lens group and slide it out carefully. I was able to clean the rear lens group and reinstall it and replaced the worn idler that caused significant focus backlash. I did NOT see any Polycarbonate or Loctite in my lens. Based on my success I have purchased a Canon 200mm f/2.8 nFD and feel I can do the CLA if required. BTW, the Canon 400mm f/4.5 is quite a nice lens with very little CA for subject in the focus plane. There is longitudinal CA on foreground and background objects. I hope to post a Youtube video of my CLA procedure. Thank you.
