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Automotive Spline

Automotive Spline

Automotive Spline


I'm in need of some help figuring out the correct way to copy a spline. I've searched through a lot of good information here but it seems there are many different standards, including proprietary and even arbitrary ones. So I thought I'd make my first post and see if anyone can help guide me in the correct direction.

The shaft I have is out of a Ford transmission. The measurements I have taken from it are:

Number of Teeth - 24
Outside Diameter - .8315"
Minor Diameter - .762"
Measure over pins - .9341"
Pin diameter - .081"

Photo of the shaft:

Now I have little to no experience with splines/gears but my searching has led me to believe this is a flat root, stub form, involute spline. I could be completely wrong.

So I ran with that and whipped up a model in CAD of an involute gear using a gear generator plug-in. The input data I used was:

Pressure Angle: 30 degrees
Module: .847
Backlash: .003"

After chopping the OD down to the correct size and lifting the root up to match, I machined a test piece out of aluminum. I had to take an extra .002" (radial) off the final product but once that was done it fit into the mating part.

The problem is when I measured the test piece over wires it came out to be .9385" when the original measured .9341". So this tells me the tooth form must be incorrect. If there is a standard out there that would fit this so that I can model it properly I would love to know what it is.

If anyone has any input for me on this it would be greatly appreciated.


RE: Automotive Spline

How about using a Gear Measuring Centre for this?

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