915 output flanges vs. 944 cv joints

[trevorbrady]

Does anyone have a good knowledge of the output flanges of 901 and 915 transmissions and the CV joints of the Porsche 944?

I have 2 pairs of output planges (both coarse splines at gearbox end, I think 17 splines or so)

one pair have 6 holes on a PCD of 94mm, only 4 of which are drilled through and tapped. The o/d of the flange is approx 110mm



the other pair have 6 holes on a PCD of 77mm, and all 6 are drilled and tapped. The o/d of this flange is approx 88mm, and there is a "lip" folded down towards the cv side.



I am trying to mate these to 944T drive shafts, but the 944 CVs have a PCD of 6x86 and an o/d of 100mm. Since neither of these pairs of flanges suit the CVs, are there CVs out there that will suit either of the flanges or are there flanges out there that will suit the CVs?

This is a bit of a head scratcher for me, any help appreciated.

[canibugu]

looks like nobody knows.

I have the same question

[Wally]

Well, I'am no 'output flange' connaisseur, but the above pair is most likely 915 late style. The 110mm CV flange diameter is typical, as are the 4 x M10 bolt holes and the two dowels. Useless for any VW-type vehicle as 110mm CV joints only come with Cv's that have porsche axle inner splines, unless of course if you can also use the porsche CV's at the wheel end, then a porsche axle of the right length can be used.

The 90mm (your 88mm) CV's are most likely VW bug CV's, so those flanges are probably from an IRS bug anyway.

I have rounded of your measurements as there are only 3 relevant CV sizes: 90mm: bug
100mm: T2/T3 busses and 944. 944 has probably different (porsche) inner splined axle size then VW busses have!!
110mm: late 911 (most, not all!) 915 gearboxes.

Simple.

[boygenius]

The turbo 944 has 28 spline axles so the turbo CVs won't fit. The n/a 944 has 33 spline axles and the type 1/ type 2 CVs will fit them. At least this is true for my 1987 n/a axles. I thought the 930 had 108mm CVs.?

[Michael Ghia]

Trev,
The 94mm flanges are stock for late 901 transmissions, code 911/** and also early 915 transmissions up to 78.

The 77mm flanges are stock for 914's and early 901 transmissions code 901/** and are stock T1 size.

The ones you want for T2/944 CV's are fitted to 911SC's only from 1978 to 1983. They will bolt into any 901 or 915 transmisison.

MG

[GS guy]

Or... you can have your output stubs modified to accept the T2 100mm CV's. I just did that for a 914 box - some of the original smaller (914/T1 size) flange was machined off, new custom machined chromoly T2 size flange fitted and welded to the stub. Finished up with nice black oxide coating - awesome work!
Work performed by Todd at Precision Alloy:
www.precisionalloy.com
Jeff