Rickresource Rickenbacker Forum

More specifically...the ferrules, or bushings. In pictures I have seen, they look like rings, but the posts look smooth. My question: how do they attach?

Second question: who's got four of 'em?

Friction fit.

I've got four of them...on one of my basses. Sorry.

BUT I know there are some forum members who might be able to REALLY help you...Hey guys!?!?!?!?

As for as Bass tuners go, they are a poor design. The case that covers the gear is held on by 4 small pins that are pressed into the plate that holds the post and gear. If these get worn they become loose, and the worm gear attached to the wavey tuning post falls out of alignment with the cog gear causing problems. They can be fixed by drilling the case and mounting plate, then using very small brass wood screws, you can mount the case cover back on the plate making them secure again. When they are functioning correctly they are a nice smooth working machine.

Got it. But how do the bushings stay on?

Wait, Paul answered...but I'm still not understanding the force that holds the rings against the front of the headstock.

I have a different understanding of friction; in fact, that's why I'm sitting down at the moment.

Mark, the rings you are referring to are what is called a "hat" bushing or "shoulder" bushing. There are serrations cut into the bushing part below the "hat" that bite into the wood when they are pressed in at the factory. I suppose if they got loose from wood shrinkage or a lot of removals they could be glued in somehow. I have a lot of grovers due to my collection of 73 4001's and think they are good tuners that make that era stand out amongst the early and later 4001 models. Every once in a while they require some maintenance but they are easy to work on....sorry but I don't have any extras, they are all installed in a bass(es) and doing their job...

Mark, unless you're sitting on a 45 degree inclined plane, gravity is what's holding you in place, not friction. The bushings are a mild press fit into the headstock. That's friction, not gravity...

Dale's mostly correct, with the exception that the pins on the Grover cases don't actually wear if they are properly staked in the first place. Staking is an operation that uses a sudden vertically-applied force (usually by a mechanical press that is set up or designed to be a "staking press"). Its purpose is to apply the vertical force so as to upset the soft metal of the pins, causing them to expand and bind against the walls of the case holes, which are designed to be a tight fit to begin with.

A fair number of Grovers were not properly staked at the factory. This caused the back plate (with the pins) and the case housing (with the holes) to move very slightly with respect to each other, every time a tuning key is turned or even when the tuners vibrated when a note was struck. This first wore away the plating inside the holes (where it is thin to begin with, whereas the plating on pins is typically thick), and then enlarged the holes to the point that there was nothing holding the parts together, and BOINNNNGGG!

Solution is very simple, and has been described here many times by Dale and others...Place tuner on dense, hard surface--a large machinist's vise is ideal, with the jaws opened to accept the string post. Using a center punch and a hammer, strike a blow on the center of each post with the point of the set, causing the pin to mushroom against the walls of its hole.

The problem is the case which holds the worm gear in place and has a lot of torque applied to it are made of Pot Metal, this is a term given to a mixture of melted down pots and pans into a semi-soft moldable material. These pins are soft and tend to break easily...Peening them back together sometimes works for a while, but soon they tend to loosen up again from the pressure and torque and the tuner separates from the case once more...This is why most all repair shops drill and place small screws in them to hold them together securely so they don't have to be repaired more than once.

Dale...are you saying that they are drilled and tapped and fastened with small machine screws
or are they drilled all the way through and screwed into the wood?

Hey, I know where you can get good #3 screws! OK, if you didn't remember the previous thread, then I am off the hook

Pot metal, as used in Grovers, is most emphatically NOT from melting pots. Although Dale made a good joke!

Cooking pots have been universally made from better stuff for at least the last 55 years

It is a term that simply identifies metals that are used for casting parts, but that do not display particularly good metallurgical properties for high strength and durability. Instead, their alloy is suited for lower-temperature and easier casting into molds or forms.


Definition of pot metal:

1. A copper and lead alloy, formerly used in making plumbing fixtures.
2. A cast iron used especially in making pots.
3. An inexpensive alloy of poor quality, usually containing lead, used especially in making castings

So, in fact, the type of metal, described as pot metal, fits Paul Wilczynski's definition perfectly of being subject to gradual wearing away and loosening, of the holes into which the pins fit "wallowing out" and increasing in size until the pins let go of their press-fit.

Indeed, an epoxy of suitable formulation would restore the tight fit, but would not hold the pins unless one files and serrated the pins around their circumference first. Not the best solution.

Likewise, the "cheap hack" idea of replacing the original pins with machine screws destroys the original design of the tuners, although it is a "quick and dirty fix" - sadly it pays no heed to proper restoral and preservation of the original engineering design and configuration of the tuners. ( I assume that this repair indeed uses tiny machine screws - what a greater horror if the repair was truly hacked up by using long thin wood screws inserted into the back of the housing itself and going through all the way to the wood itself )

I think that re-tightening the pins in the original holes is the best idea, by the use of an appropriate staking station and enough force to do the job right, correcting the factory flaw of having staked them originally with too little force.

Understood...

Elys, you obviously know very little about the repair or restoration of Grover cast metal tuners as your rhetoric answer implies: "cheap hack" "quick and dirty fix" Ben to answer your question: This is the way that not only I but the Grover Corp. suggested how to fix these tuners in the mid 70's when this problem started turning up. 1st they sent out warrantee memos to music stores offering replacements for the faulty tuners, and to warrantee repair shops, we were offered compensation to repair them using this method: remove the cast metal case, file and level the edge of the case that the pins are a part of. They implied that all 4 pins be drilled, but I found that only drilling 2 opposite corners with a .040 drill on the underlying edge approx. 1/4inch deep, while retaining the other 2 pins did the job. The small brass screws I use are approx. .065 diameter, flat head, flat blade screw type. The reason to use brass screws: it matches the density of the metal of the cast casing. The holes in the base plate are where the screws go thru, after tightening these they can be easily filed down level with the the base plate so that when they are put back on the instrument you can never tell they were repaired. If you have a set that needs repaired and don't want to take a chance on doing this yourself, send them to me and I'll fix them as I've been doing for 32 years. It only takes about an hour to do all 4.

That's not a proper restoration. Ad hominem is not appropriate for you here, Dale. If your only defense is to belittle someone else, then only you are the minor party afterwards.

The criteria in true "restoration" is that when you are finished, is it indistinguishable from the original factory job, or not? Your way is NOT.

I would think that if this method which Dale uses is a Grover factory-approved repair procedure that was used in the period when the tuners were installed on Rickenbacker basses as original hardware, then I see little need to debate the issue.

It compares to coming across a car many years later after a recall or other special procedure was performed. It is reasonable, right and proper for solving the problem in it's original context. Both roads lead to the same destination.

Or, as I am wont to say, Peace. Love, Led Zeppelin!