Well, my Omni D has been needing a PTO job for a while... Tuning was getting more and more "thick", and finally it got to the point where I could crank the knob forever and the tuning wouldn't change much. So I took it apart this weekend. Everything looks ok in there, it's just that the grease they used dried out. I've seen it described as "chewing gum"... Yup. It's been in there since 1979 (found a date written on the PTO box), so I suppose it's not that surprising. Quite a pain in the butt cleaning that off of all of the small parts... Inside and out. Soaked them all in denatured alcohol for a while... Which didn't actually seem to help that much. Then lots of careful wiping with bits of paper towel and tweezers. There is a hollow brass shaft that has to be cleaned on the inside... Fun. But anyway, that part is done. Only re-greasing (Mobil 1 synthetic) and reassembly remains. It was relatively easy to get it apart, following the instructions... It's just a big, sticky mess to do the work. At least the thick grease keeps small bits from flying around. Looking forward to the results.