Shift Knob Adapter

First off, Happy Tech Week. I've been saving these pictures since this summer just waiting for the next Tech Week.

I bought this shifter at an auction for my Model A sedan, I spent too much, but fuck it I like it.
My first idea was to make an adapter from a short bolt that would thread into the Knob, then I would drill
and tap the bolt to match the treads on the shifter arm. I could not locate a bolt without special ordering it, so
on to plan B.

Plan B:
I did find a Cup point set screw to match the Knobs inside thread of 5/8-18 Fine thread.
I then just setup the tools I needed and got to work:

(Pic 1) kind of blurry but you get the drift.)From Left to right: Center drill, Tap drill, Taps Set screw, and Shift arm .
Next I used some aluminum shim material to wrap around the set screw so not to put a flat spot in the threads.
I used a V-block and clamp to hold everything vertical, and clamped the V-block to the Drill press table.
Before I clamped The V-block to the table, I put the tap drill in the chuck and moved the work piece until it was centered under the drill bit.
Since I used a cup point set screw, there was all ready a centered drill mark, so centering the new drilled hole was quite simple.
After I found center I clamped everything down at started drilling.

(Pic 2) You can see the shiny spot in the center of the set screw, That is the beginning of the new hole.

(Pic 3) At first I was worried about the set screw spinning when I started drilling, so I put an allen wrench in the set screw from the bottom side and
clamped that down as well.

(Pic 4) After the hole was drilled, I tapped it. Kind of of self explanatory but remember to use a cutting fluid of some kind and take your time.
I did use a nice little tool to help center the tap. (top of the pic in the drill chuck) Its just a spring loaded center point that keeps every thing
straight and under pressure while your tapping. I've used it in the Lathe, Mill, and Drill press. Its nice to have but you can get by without it.

(Pic 5) After starting the tap in the drill press, I moved the piece (with the tap still in) to the vise. Just a preference I guess, I've always had better
luck tapping like this. I would guess that I have about 1/2 the length of the set screw tapped. I didn't go all the way because I wanted a hard stop
when I threaded everything together.

(Pic 6) After tapping its time for a trial fit, Just right. I used the allen wrench the cinch the insert down and lock it in place. I wanted the insert to stay
with the shifter arm and not the knob.

(Pic 7 & 8) Trial fit of the Knob

(Pic 9 & 10) Finished and in the Car, Time for a Drive!


Thanks Jeff

 

Thanks for the info, good idea.

I'm lazy so I just drill them out drop in a hex nut with a bolt in it to save the threads and fill with epoxy or panel bond whichever is closer.

 

Thanks Jeff, Clean job and cool tip. Slim

 

Wow, that is a for real old 30s-40s Onyx shift knob, onyx meaning glass in this case.
There were actual stone ones being made too but the glass ones were available in many colors. There were also different shapes, oval, large, small, banded ball, round and flattened ball.

Good bit of tech to use these. Thanks.

 

all tech week to the top 3

 

great idea as you can never find bushing you need.

 

I bought it at an antique auction, I think it fits better in my Sedan than in some ladies hutch, or some dudes shop.
Next step is to Chrome the Shift arm.

Thanks Guys, Jeff