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Exploding grovers
Posted: Tue Apr 03, 2007 10:34 am
by brycycle
i just purchased a '72 4001 w/ the original grovers.
can someone explain how they fail and if there is anything that can be done to prevent this from happening?
thanks
Posted: Tue Apr 03, 2007 10:48 am
by elysrand
The original Grovers with flat tuning keys and an enclosed back often suffer from the backshell coming off. They are pinned in place by four metal pins, one in each corner. During manufacture these pins are inserted, and tapped or hammered lightly to secure them.
I have had a few loosen and come off. When that happens, the gear comes loose from the pinion shaft as soon as the tension of being tightly wound is released, say when you are changing strings. If you hold the cover in place while tightening them back up, the sideload (or twist) will again hold the loose pins in place.
Although a royal pain, everything still works OK until next time
To really fix it, you must hammer and spread, or as a lesser fix bond with a suitable adhesive in some cases, the pins back in place. If you lose one, you are toast. You have to fabricate another from similar diameter cold-rolled or drawn steel. Soft wire does not do the trick.
That exhausts my knowledge, and others here like Paul W. can likely offer more detail and more practical smarts
I repaired mine by malleting the pin heads a bit oval and pressing them back into place. Did a light lube job with silicone grease while I was in there, smooth action now

Posted: Tue Apr 03, 2007 10:48 am
by rhampshire
The pins weren't swaged properly from the factory causing them to come apart. You need a center punch and a hammer to re-swage the pins.
Posted: Tue Apr 03, 2007 12:10 pm
by dswp
Do what I do.
Buy lots and lots of spares...

Posted: Tue Apr 03, 2007 12:30 pm
by brycycle
if only it were that easy Dave...though now i know who to bother if anything goes awry...
Posted: Tue Apr 03, 2007 12:40 pm
by jingle_jangle
Grovers on the march...
Posted: Tue Apr 03, 2007 12:51 pm
by rickfan60
Just swage them with a hammer and punch.
Posted: Tue Apr 03, 2007 1:36 pm
by jwr2
replace the grovers with schaller m4 turners and take a hammer to the grovers ...
Posted: Tue Apr 03, 2007 1:37 pm
by elysrand
Just like "Babes in Rickland"

That's a lotta nice tuners ya got there, bud!
Please, don't savage them, Ted!
Posted: Tue Apr 03, 2007 1:43 pm
by elysrand
Better to wear out the Schallers and then 30 years later put the Grovers back on and sell it for $25K on sheer-nuts eBay

Posted: Tue Apr 03, 2007 1:58 pm
by brycycle
are Schallers a drop in replacement?
Posted: Tue Apr 03, 2007 2:01 pm
by kcole4001
Not all wavy Grovers have problems. JH posted that it was only a certain period that had the swaging problem due to (I think it was) a change in manufacturing location.
The ones on my '81 4080 are pretty solid, & I like the look, myself.
Posted: Tue Apr 03, 2007 2:03 pm
by brycycle
well, this '72 won't be my everyday bass, hopefully after they are swaged (if needed) i can let them be.
thanks for all the help.
Posted: Tue Apr 03, 2007 2:07 pm
by elysrand
Bryce, at least not on my 1968. It had the reverse Klusons with the slotted screw, and someone replaced them with Schallers. With apologies to Jeff, it sank its value like a rock, but the installer had to fabricate an adapter plate with the original hole for the Klusons, which have a similar larger footprint to the Grovers, and a smaller set of threaded holes for the smaller-footprint Schallers. Definitely not a drop-in replacement, you will be cutting new holes in your headstock and the old holes will be exposed. A moisture-entry point for sure

Posted: Tue Apr 03, 2007 2:34 pm
by marc61
i keep my Grovers where they belong, at home, in their original box, where they remain unused.