Hi Chris,
I think I just answered an email you sent to me. If the bass is the one you wrote to me about, then it's not a Stanley Clarke model, it's much older.
For others following this thread, here's my reply:
If the problem is the tuners, then yes you should get replacements. However, this is not simple.
You likely have Schaller tuners with the anchor screw pointing towards the bottom. The replacements have had the anchor screw pointing toward the center of the peghead for over 30 years.
The Gotoh tuners have the anchor screw in the correct place, but the shaft is a bigger diameter, so you have to enlarge the mounting hole to use them.
You can replace with current Schaller M4 tuners and just leave that extra screw in the original hole so it doesn't chip there.
But, you should first determine if the tuning peg is the problem. The internal gears in the Schallers are brass and will wear with lots of use, so it's not out of the question. Generally worn tuners will make the
tuning go flat as the tension is released by the gear.
Inspect the slots in the nut and the bridge saddles as well. Make sure there are no burrs on them that can catch a winding and then release it later at an innoportune time. This is also usually a flat tuning issue.
The fingerboard is usually not sealed, so there is moisture exchange. Make sure you are practicing good fingerboard hygiene and that it's oiled once or twice a year to help protect againt it. If the fingerboard takes on moisture, even a little, it will gat a little bit bigger (longer) and that can make the tuning go sharp.
There is another issue - when you get really good at hearing what the strings do, you cna hear all sorts of horrible things. Like I hope you never learn how to hear the fourth or fifth harmonics on a sustained note:
you will never be able to tune your bass again! Trust me on this one, it's hard to ignore once you hear it.
Also, is this the same with all strings you've tried? How are you winding the strings on the pegs (send a piture or description).
Hope you have a nice Thanksgiving.