(See my WPS AMC page for more of my rambler hacks.)
The Flash-O-Matic column shifter on my 63 Classic has never been right. It's sloppy, pops out of gear ... that's in addition to the chronic turn-signal problems.
The soft pot-metal castings are the main problem. The shift lever is steel, with a hardened tip that rides in a too-thin cast channel, and the pivot is a roll-pin. The hardened tip of the shift lever transmits the force of your arm onto the shift tube via a tiny contact point in the potmetal. Once that wears away, which only takes a few years, the force is instead applied to the pivot. Eventually the lower hole becomes oval, the lever moves all over the place, and the slop lets the hard shift-lever detent pop out of the gate inside the column. It's a mess.
After fooling around with half-measures I believe I've found a real fix for it. You can apply it to badly worn columns and it should last longer than the original. The fix is completely invisible and uses all the stock parts including the roll pin.
My steering column behaves like a new car, or better. The shifter is CRISP and snaps into the right position.
The fix consists of two parts:
In the pile of columns I went through trying to find good parts, I discovered other weak areas I was able to fix as good as or better than new.
Photo #1 shows the steering column in the car, and photo #2 shows the unmodified shift-column section as indicated. All of the work is done in this part. The numbered items, described later, are: 1) the screw-access wells, 2) the shift-lever tip, 3) the channel in which the shift-lever rides. A drill bit replaces the roll pin while working on the bench.FIXING THE PIVOT TIP:
The tip of the shift lever rides in a vertical channel with very narrow sides. Due to the shape it would be difficult to repair. But a fortuitous design feature makes for a five-minute fix!
It's hard to see in the photo, but the very tip of the shift lever sits in a slot, extending just beyond the screwheads to the left and right of it. The tip penetrates the channel only 1/16" or so; it travels up and down the slot as you pull the shift-lever forward to change gears. The tip wears the thin lip of the channel away quickly.
There are two circular wells that provide access to the screws that hold the shifter detent spring assembly in place, about 5/16" diameter and about 1/2" deep. The fix is almost trivial:
As you can see in the right-most photo (assembled without grease for the photo) the rod tip now rides along the edges of the rods. Though the contact area is radiused, the rods are much harder (though still softer then the hard shift lever) and the force is transmitted to much more of the casting area than before. Mine was slightly tight initially, but I'd avoid removing metal.
Be careful that the dropped-in rods don't drop-out
when you're working on the thing. Once the column is assembled, the
shift gate in the next-higher column section (that contains the
directional switch and horn slipring) prevents them from falling
out when you tip the car on its roof (you might have other worries
if that happens).
FIXING THE SHIFT-LEVER PIVOT:
Unfortunately I didn't take enough pictures here, but the task, though more work, is pretty simple. You'll need a drill press and a big vice or some way to clamp the shift-column section, lengthwise.
Essentially, the trick is to drill the ovalled hole out large enough to accept a home-made insert (similar to the Helicoil trick) made of a section of bolt or threaded rod.
The trickiest part is actually determining where to drill the hole. Since the bottom hole ovals badly it's hard to get a "center" from, and you don't want to miss, or the tip of the shift lever won't be centered in its channel.
Here's how I approached the problem:
As far as I'm concerned, the whole thing is suspect. The tapped holes that hold the hard-steel shift gate were pulled; the screws are too small for the load. I deep-drilled, retapped, degreased and used low-strength Loctite. Before I did this it shifted slightly in operation, adding to the sloppiness.
The next-higher column section, containing the direction switch, was just as bad. The threads on two columns were also pulled, overtightened at the factory, and the directional switch assembly was loose.
(Be careful tapping potmetal with a 6-32 tap! It's gummy stuff, I almost broke off a bit and I was paranoid to begin with. I found I had to completely remove the tap every 2 -3 three new cuts and clean the tap. Slow, but easy work.)
It's not as much work as it sounds, once you have the column out, or like I did, built a new column from parts and repainted, and installed when I did some front end work. It was worth every bit of effort!