Tuner Replacement

[OldMandolins]

Do you believe it would hurt the value of this mandolin if I were to replace the tuners ( Dates from around the 1800's , possibly Italian )? The mandolin had repairs that date back to the 40's or 50's so thus the current tuners were replace then are currently rusted and stuck. I was eyeing some grover tuners. Do you believe that a style A will fit?

[MikeEdgerton]

Two things you need to know. You need to know the spacing center to center of the posts and it they are worm over or worm under. If t's that old they are most likely worm under but the spacing is probably not the modern spacing. You're going to need that measurement. Don't worry about the value of the instrument as there are very few old bowlbacks that carry a high value and they will be labeled. I don't think it's quite that old.

The Grover tuners you're asking about have a measurement of .906 inch or 23.01 mm center post to center post and are worm over. Stewmac makes a restoration tuner that fits early Gibson models that are .931 inch or 23.60 mm. Those are pretty much your choices unless you go for a used older set. It's always an easier task if the old tuners can be resurrected.

[OldMandolins]

Yes I see that they measure just over .9 . Is there any other company that you know of that do make tuners that will fit early gibson models ? I do want to resurrect the old tuners but they are stuck. In your opinion what would be the best way to "free" them ? Attached are some closeups.

[Marty Jacobson]

Those tuners are toast, and were probably never great to begin with. If you order from a company with a good return policy, your risk in trying a set of tuning machines is low. If they work, great. Otherwise, come back and we'll try to help you figure it out more exactly.

[OldMandolins]

I think that is what I will do. Do you know of any newly made tuners that will fit ? Isn't the difference between the Style A and restoration tuners too close as to cause a problem in installation ?

[Marty Jacobson]

The difference between restoration tuners with a spacing of .931"/23.6mm between posts, and standard mandolin tuner spacing (.906"/23mm) is indeed enough to cause problems. There are also other spacings which have been used in the past, but they are pretty rare. Unless you want to figure out how to measure the post spacing more precisely, you won't know for sure. The best way to measure post spacing is to measure from the outside to outside of the existing posts with a digital caliper, then measure one of the posts and subtract that from the total distance you originally measured.