100mm CV Joint Spline Count

[metrod]

Hi

I have a 77 911 with 100mm CV joints, I have checked around the forum but can't see anywhere which tells me what the spline count is?

I found the 108mm for the later cars 85 on and they appear to be 28 but are the 100's less?

Thanks

Nigel

[safe]

27

CV and Axle Cross Reference

[0396]

Safe,
Excellent info.
Thanks

[metrod]

Excellent Work

Thank you very much

Nigel

[safe]

Tom Butler deserves the credit, awesome information in that thread.
I have had good use of it.

[KTL]

Was doing some searching on this issue for some lightened CV joints (Taylor Race Engineering has them) and it turns out the spline count is actually 25 splines for the '75.5 to '85.5 100mm CV joint. Just wanted to clarify that since safe's post above says 27. 27 is actually the diameter of the splined axle, not the number of splines.

[safe]

Originally Posted by KTL

Was doing some searching on this issue for some lightened CV joints (Taylor Race Engineering has them) and it turns out the spline count is actually 25 splines for the '75.5 to '85.5 100mm CV joint. Just wanted to clarify that since safe's post above says 27. 27 is actually the diameter of the splined axle, not the number of splines.

There are two types of 100mm splines, corse and fine.
The 944 turbo used the 25 splines if I'm not mistaken.

[chris_seven]

I am sorry to disagree but I don’t believe that the 100mm CV Joint used on a 911 has 27 splines.

I am sure that all of the 100mm diameter joints used on a 911 have 25 splines.

There are 33 spline and 28 spline variations of the 100mm joint in the 'Motorsport Catalogue' but they are not commonly used.

The transmission flanges used on the 915 output flanges from the diff have coarse and fine variations but not the CV Joints.

[wayner]

More data points:

The early 915 (before 1975) were 108 in diameter.
They use 4 bolts and two pins to mount the CVs

After that they got smaller100mm.
(later they got bigger again in the 1980s but used 6 bolts as did the 930).

1975 911 hubs and CVs are 100mm, but the 100mm 911 transmission flange has a finer male spline

Here is a reference
CV Joints 101

And another
CV and Axle Cross Reference