Does anyone remember what size and brand of neoprene washer to use on the tuning mechanism? What the part number is. My AK is a model 856. I remember someone once giving the brand and part number of a washer used in plumbing that I could get at Lowes. Thanks, John

:
FWIW (possibly not much) I have used a short section of automotive rubber hose for this purpose. I don't recall the hose inner diameter (ID) that I used (it was 33 years ago), but it just needed to fit very snugly over the drive shaft. My guess would be 3/8 inch ID. You only need a section about half an inch long. As it turned out, the hose outer diameter (OD) was perfect to engage the toothed driven wheel. Fabric-based hose (fuel line hose) will last longer than straight rubber in this application since it resists splitting much better. That's what I used decades ago and the repaired set still tunes perfectly.