Headstock slide lock doesn't work

[billmayo]

I have only replaced or sold less than 10 lock wedges and 3 lock rods in the past 10 years. I use a hand wire brush to clean the lock rod threads before trying to rotate the lock wedges. When I cannot rotate the lock wedge with my fingers after cleaning the lock rod, I remove the lock rod and wedges from the headstock. I have both a left and right hand thread tap for the lock wedges if needed. If the lock wedge threads are badly damaged, I replace the lock wedge. If the lock wedge angle has an indent in it, I file the angle flat either in the headstock or when removed. This seems to improve the locking capability of the headstock.

I believe the main reason the headstock lock handle is overtighten is because of wax, sawdust & dust in the headstock way tube holes. This prevents the way tubes headstock holes from maintaining a tight connection with the way tubes. Using a few twists of fine (150) sandpaper in the headstock way tube holes helps restores a little more grip for the headstock. The lock wedges are not what prevents the headstock from moving/slipping on the way tubes, they only to force the headstock casing way tube holes againest the way tubes.

These are steps in my headstock rebulding check list.

33. Clean interior of headstock casting, including removing impacted grease/dust in quill advance mechanism and remove wax, sawdust & dust (crud) from way tube holes. Lightly sand way tube holes with fine (150) sandpaper to insure good contact with way tubes.
34. Inspect headstock casting for cracks or breaks.
35. Clean & check headstock lock mechanism & dry lube the rod. File the lock wedge angle or replace lock wedges if needed.

Email me if anyone is interested in my headstock rebuilding checklist. Thanks.