Author Topic: Next Drive shaft question  (Read 269 times)

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Colin Byrne

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Next Drive shaft question
« on: May 19, 2020, 03:13:04 PM »
So managed to sort out my mismatched inner drive shaft/engine mount situation (thanks again Ben ).  Next on the list is the choice of CV/Drive shafts.  Due to the track of the car It looks like there is no way around getting some custom shafts made up.  I've based my new rear uprights around a Peugeot 205gti hub as they are a 108 pcd, same as the 105's, have a large 42mm bearing surface and have a 25 tooth inner spline, same as many FWD alfa's and the Lancia beta.  But once again luck was not on my side and the Peugeot appears to run a different pressure angle spline than the alfa, so the Alfa 25 tooth CV joints don't fit.  The Matching Peugeot CV joints have a fairly small inner spline, so not super happy about running those.
 
The option i'm considering at the moment is to get the Peugeot drive Hubs re splined to match an Alfa CV.  I have some drive shafts from the 166 that i got with the engine.  The outer spline of the CV is 27 tooth and looks to be just large enough to be re-cut into the hub (ie the minor diameter of the 27 tooth is larger than the major diameter of the 25 tooth.

This will not be a cheap exercise! however i don't want to be breaking drive shafts and cv's the first time (or second) i take the car out.  and the 28 tooth outer spline axles look to be pretty chunky indeed

So from what i've managed to find online, the 166 looks to have the biggest combination of axle/cv splines of the Alfa family?  27 tooth outer spline and a 28 tooth inner.   looks like a lot of the 2L cars run a 25/25 and some of the 3L run a 25/28. 

As i said i've got a couple of CV's already, but looks like the availability of new 166 CV's is OK

I've also read there's availability issues with the GTA CV's? does anyone know what spline combination they run, looks to again be a 28 inner, not sure of the outer though

any comments/info/harassment most welcome?
cheers
« Last Edit: May 20, 2020, 09:29:51 AM by Colin Byrne »
72' 105 2000 GTV Red (tarmac rally/race car)
74' 105 2000 GTV Blue (road car)
68' 105 1600 Giulia Super White (Not sure yet)
01í Nissan Pathfinder (Tow car/Alfa support vehicle)

105gta

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Re: Next Drive shaft question
« Reply #1 on: May 20, 2020, 08:30:22 AM »
Hi Colin, Iíd suggest having a look at the rear outer of a GTV6/75. They have an adaptor on the outer cv through the hub. Off the top of my head itís 27 spline but would mean that both inner and outer cvs would be the same. As you donít need the articulation of a FWD outer cv it would mean carrying one type of spare and on The plus side. Itís also a Porsche 930 cv.(From memory) Probably the most commonly used cv in motorsport. Meaning there are plenty of cheap and expensive options/up grades depending on power levels etc...
I think I have one floating around the garage if you want me to measure one up for you.
Ben
1967 Giulia Sprint GT Veloce (WIP)
1985 GTV6 (WIP)

Colin Byrne

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Re: Next Drive shaft question
« Reply #2 on: May 20, 2020, 04:21:37 PM »
Thanks ben, I really like that idea unfortunately i don't think they will fit my uprights, the cv mounting flange is close too splined section and won't clear the upright, we're as the CV's with the integrated spline, have a taper on them so the bigger diameter is set further back.  You know i bet if i'd started with those and designed the upright around them i might have even been able to use the GTV axles as well, they look about the right length!, i'll just put that in the already full bin of, i should have done that ...

so apart from that i think the 166 axles are winning so far
72' 105 2000 GTV Red (tarmac rally/race car)
74' 105 2000 GTV Blue (road car)
68' 105 1600 Giulia Super White (Not sure yet)
01í Nissan Pathfinder (Tow car/Alfa support vehicle)

105gta

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Re: Next Drive shaft question
« Reply #3 on: May 20, 2020, 05:25:02 PM »
Ha come on Colin, you have the skills and the equipment. You could always make your own outer half shafts, (cutting external splines is way easier/cheaper than internal) but with a conical flange like the factory did with Dinoís etc... and keep the simplicity of universally available CVís The V6 transaxle carís axles come in long and short lengths. GTV6 are shorter by about 30mm would that much Clear your uprights? Then you could also cut th e splines to match your already existent outer wheel flanges 😉
Ben
1967 Giulia Sprint GT Veloce (WIP)
1985 GTV6 (WIP)

Colin Byrne

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Re: Next Drive shaft question
« Reply #4 on: May 20, 2020, 07:17:44 PM »
Haha, I like your thinking! It would mean I'd have to by an indexing head setup for my mill, and I just hate buying new tools... I could modify the peugeot cv and add an alfa drive flange, only issue is the cv would then be much further in board, end up with some pretty short axles, do you know how long gtv 6 axles are?
72' 105 2000 GTV Red (tarmac rally/race car)
74' 105 2000 GTV Blue (road car)
68' 105 1600 Giulia Super White (Not sure yet)
01í Nissan Pathfinder (Tow car/Alfa support vehicle)

Colin Byrne

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Re: Next Drive shaft question
« Reply #5 on: May 20, 2020, 09:26:01 PM »
actually looking at a few photo's on the web, the inner drive hub may be a bit longer than i thought, if you do have one you can measure that would be great, the thickness of the flange, the distance from the back of the flange to the start of the spline, the spline length and the thread length should be enough info to get me into trouble!
72' 105 2000 GTV Red (tarmac rally/race car)
74' 105 2000 GTV Blue (road car)
68' 105 1600 Giulia Super White (Not sure yet)
01í Nissan Pathfinder (Tow car/Alfa support vehicle)

105gta

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Re: Next Drive shaft question
« Reply #6 on: May 22, 2020, 04:12:28 PM »
Hi Colin I thought itíd be easier to draw you a picture. No fancy CAD stuff like you have but you get the idea 😉
1967 Giulia Sprint GT Veloce (WIP)
1985 GTV6 (WIP)

105gta

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Re: Next Drive shaft question
« Reply #7 on: May 22, 2020, 04:13:47 PM »
Actually I think the threaded holes are 10x 1.25 but Iím partially blind at the moment so a bit hard to tell.
1967 Giulia Sprint GT Veloce (WIP)
1985 GTV6 (WIP)