View Full Version : How to make a splined hole fit existing spline

Your Old Dog
05-12-2009, 08:39 PM
I would like to remake a shifter for my Harley. The stud sticking out of the bike that the shifter fits on to is splined. I was thinking on turning down some tool steel, using the straight knurl on it, heat treating it and then putting a slight concave in the end with a dremel stone and then forcing it through the hole of the shifter I am making. It's a bit of work. Anyone think of a better way to accomplish the same?

05-12-2009, 09:24 PM
Use a slotter or shaper, manual or power. You could also use a die filer, or hand file.

05-12-2009, 11:17 PM
Well, this may or may not fit your request.

Anyway, In the repair of several robotic material handling devices, it was necessary to fabricate something such as you speak. In my case, it was to design interchangeable cams and levers of nominal sizes for actuator speeds dependant to lever lengths.
The levers for the most part were of aluminum, steel and brass.

It was necessary that each lever have internal splines so to install and be universal. The machines these would go on were not of ordinary design as each were unique to said applications.

It was necessary not only to fab the levers but the protruding splined shafts
as well. Each as said, were of varible sizes from 1/4" thru 5/8".

What I used to create these assemblies was to use "Wheel Studs".
These were made of high carbon steel.

Stud: Make two.

Screw stud into a threaded mandral and face cut head to splines.
Concave face using a ball endmill or bevel cut.

Same as above with the exception of turning a few thou from the splines diameter.
This serves as a pre-punch before using #1 providing for clean cut splines.

Each lever was drilled and reamed to size. Bevel cuts were made to each side of thru-hole. This served as a clean approach and break-out for the stud broach.

Studs were used as standard punch type broaches.

For your application, there are many different sized diameter studs.
Some have knurled splines while others have cut splines. Finding one to match what you seek may not be differcult. There are hundreds of Imperial and Metric sizes available.

Below is a site listing only a few.
Do a little homework and you may find just what you're looking for.


Also go to http://www.Thomasnet.com and search for manufactures in re:

It worked for me, and perhaps it may work for you.


05-13-2009, 02:43 PM
What is the OD and number of splines on the shaft?

05-13-2009, 02:47 PM
Depending on material, depth , etc, you might look at how a rotary broach works for some ideas.
I suggest watching the videos too.

05-13-2009, 03:28 PM
could you take a used shaft and cut it down to build your tool and then press through?

leon holmes

05-13-2009, 03:56 PM
Made a heal & toe change for a Sportster (splined shaft).
Machined the lever, set up in dividing head & cut the spline grooves with a V-tool in a boring bar for a sweet fit on the shaft. Split the boss and locked to the shaft with a stainless cap screw.

05-13-2009, 04:28 PM
Mine has a extended shifter on it. Reduces effort.

Longer shifter means more force.
Remember when you make the handle to the "cam drum working the "shifter forks" and top hats, sliding the gears and synchronizers with more force you can FUBAR something up.. (hell I can break a anvil, I have)

As long as you know it..

And the problem is? too short to be comfortable or a big spline making indexing not moveable..

Personally, I'd purchase another to suit yourself. Ain't nothing like a bike sitting on the side of the road stuck in one gear.. OR slam boxing it home cause the clutch cable screwed.


05-15-2009, 09:04 AM
Depending on material, depth , etc, you might look at how a rotary broach works for some ideas.
I suggest watching the videos too.

And How much would this tool cost ?

Complete & ready to go, with the tooling for that spline ?

Don't be shy...

05-26-2009, 03:52 PM
I think a custom precision ground tool steel spline broach like the one described in the first post starts at about $300.

05-27-2009, 07:12 AM
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