Possible Schaller tuner problems?

Hi all. I recently bought a ‘97 Comanche. I’m having trouble with keeping it in tune. For example, if I don’t use the trem I can bend strings all day long and it keeps its tuning. Once I dive bomb or pull back it doesn’t return to pitch. I thought it might be the nut, especially since it is a 22 year old guitar, so I cleaned up the nut using older wound strings in the slot (like a file) and then lubed it up with chapstick and pencil lead (has always worked on my strats). The problem continued. It has frustrated me, because the normal indicators of nut issues are there: dive bomb and release = some strings remaining flat, and on pulling back, some strings remain sharp.

During the course of the diagnosis, my 6th and 5th string tuners (E & A) felt crunchy at some points during the tuning process. Upon further investigation it seemed as if the tuners may be slipping internally with the changes in tension.

My question is: do you know if the tuners user-serviceable? I’ve already tightened the nuts on top (that hold the tuners in place). After removing the tuner keys, I have also tried to force grease into the shaft where the shaft enters the body of the tuner, but to no avail. In the event they are not serviceable, any ideas where I can get replacement tuners for a decent price?

I’m going to be installing a new pickguard soon so since it’s going to be on the bench I figured it’s a great time to look t everything: tuners, pivot posts, knife edge, etc. I’ll have my 3-in-1 oil and grease at the ready too!

Thanks in advance!

Mike

PS: I also sent the same message to the G&L repairs inbox, but I know they’re pretty busy and may not get a chance to respond right away, so I posted to this knowledgeable group!

Without hearing anything about the rough tuners I would have guessed the problem is worn bridge posts/knife edges; maybe someone tried to turn them under string pressure. I would take it apart to inspect - a certain range of damage can be corrected with a file and some white lithium grease to smooth out worn knife-edges.

Everyone says the nut is ‘usually’ to blame for tuning issues, but in my experience with two-point vibratos, it tends to be the bridge itself if anything goes gravely wrong. I’m not saying the tuners are not somewhat at fault or in need of replacement, but in my experience I’ve never encountered even very cheap modern tuners that wouldn’t at least keep tune, even if they felt rough/loose/sticky. Of course if you see them visibly slip that’s another matter Not familiar with whether they can be lubricated or if it would help. Good luck!