Porsche 930 CV conversion axle length?

[Syncroincity]

My brain hurts...
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'86 Syncro CHC Top AAZ Turbodiesel
'04 Passat Variant 4Mo 5MT

Vanagon Build: http://www.thesamba.com/vw/forum/viewtopic.php?t=466866&highlight=

[Syncrozilla]

[syncrodoka]

[SyncroGhia]

[Syncroincity]

OK, KISSing it, how about just dabbing a couple or 3 of tack-welds into the splines at the point where you want the plunge to stop instead of machining for another snap-ring? Not like it's load-bearing or anything, and could be filed flat where it meets the CV star. I say this because I have easier access to my welder than a machinist.
_________________
'86 Syncro CHC Top AAZ Turbodiesel
'04 Passat Variant 4Mo 5MT

Vanagon Build: http://www.thesamba.com/vw/forum/viewtopic.php?t=466866&highlight=

[syncrodoka]

I would be worried about the welding heat affecting the heat treatment that alllows the axle's torsional abilities.

[Syncrozilla]

I'm sorry but welding on the axel is a HACKER move! Do you also have wires twisted together with a little electrical tape around them in you electrical system? How about sheet rock screws? They also show the special skills of a vehicle owner.

Ever try to weld on spring steel?
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Please do not message me on TheSamba. Use my email, [email protected]

[syncrodoka]

[derekdrew]

One benefit of the circlip at the outer of the axle seems like it is just for space. But where are talking about the axle side of the CV joint where the 930s are (front inner or rear inner and rear outer), then one could use fatter things, like a hose clamp or cv joint clamp or permanent clamp and to make it stay, maybe grind the ridges of the splines on the axle down at that point so the axle would be slightly narrower there, which would make it very hard for the clamp from moving along the axle. In this way, one might be able to avoid going to the machine shop with the axles except for the front outer position? Then, to top it off, maybe try red loctite on the splines in between the cv joint star and the axle for whatever that is worth. I measured very carefully the amount of plunge needed for a front stock suspension where the suspension drops down 1" further than in the stock setup, and even with the extra 1" drop, the plunge requirement up front is basically near zero. So, theoretically, you don't need the axle to move inside *either* joint, and all the movement would do is introduce wear (of an amount that some have said could be material to us). Not only that, but even the use of 930s seems to be quite unneccessary (in the front) because the stock vw oem 108mm joint has more than enough plunge in it for the job. I don't know whether the use of front A arm ball joint spacers would introduce a plunge requirement, or whether a Burley A arm would do so. I'd love for somebody to measure those cases. But it is hard to measure without precision measuring equipment because the range of plunge is so small. At the back outer position, I also favor the idea of a bagel (maybe plastic or hardish rubber, but otherwise like duncan doughnuts or a bagel) which is HOLLOW and cut in half through the middle and this being slid onto the axle inboard of the CV joint and affixed to a specific place on the joint. The idea here is that the outward force of the axle load then is distributed away from the star center and to the fixed outside edge of the CV joint, just under the rubber boot. The primary purpose of this is to encourage the CV joint to run with the star centered in the middle of the cv joint rather than over to the outside, which might otherwise happen when the weight of the axle is pushing the star outward. Long-term or frequent high power out-of-center CV joint operation has been raised as something that might not be optimal practice for 930s, and the hollow cut bagel device, for lack of better terminology, would put that concern to bed. The reason for the bagel being hollow is to make sure it does not contact the cage. Now that you have the idea of the bagel, the concept could just as easily be rendered with a metal spring about 25mm on one end and 103?mm on the other end, maybe 2? inches long, and affixed to the axle. I took out www.syncromadness.com but there is nothing new there you have not seen already, and all that stuff is from the early 1990s when I wondered about my sanity and did not have you pals around to make me feel like I was behaving as a normal person might. I am waiting for Seth to say that Loctite on CV joint splines is hacker stupid, since I really don't know.

[Syncroincity]

[SyncroGhia]

Just a bit of info on front inners..

I'm running 50mm longer front shocker pins, Burleys top arm spacers and Porsche 944 CV joints for inners and Syncro 16 outers and on full drop (the arm rests on the spring rather than the shocker topping out), the inner CV joint is very close to going into bind. It doesn't go into bind but if I pull down hard so the top arm pushes the spring out of shape a bit, it does.

I'm looking to replace the front inners with Syncro 16 rears when I replace the driveshafts. So far they're doing ok.

MG
_________________
T3 Syncro 16 S6 Westfalia Limey SOLD
T3 Syncro 6x6 SOLD
T3 RS6 Bluestar
T3 Tristar Syncro 16 SOLD
T3 Tristar Syncro RHD SOLD

[syncrodoka]

Does anybody see any reason to not polish the 930 CVs before I install them?
http://www.dune-buggy.com/techtips/cv_joint_polishing.htm
I also found a good idea of determining the axle length then getting a dowel of the same length and cycling the suspension up and down a few times to double check length
http://www.shoptalkforums.com/viewtopic.php?f=28&t=123409&start=15
I am working 60 hr. weeks right now and won't be able to actually take apart the truck and get some hard numbers until next weekend.

SYNCROZILLA- It looks like I will be looking to have the front axles machined. I am chasing down the parts and a front locker right now.
If anybody else wants to get some machined for future use, it would be a good time to get it done. Sometime next month when syncrozilla has time.

[Syncroincity]

Polishing will supposedly extend the wear life of the CV... it's one step in the "race prep" many shops and vendors offer, along with radiusing any sharp edges and stress points. Refer to my photos on page 1, showing one out of the set I got used from an off-road buggy... polished & race prep, with chro-moly cages & hardened stars. (the outside is polished strictly for looks on a car where the suspension is exposed) I also picked up a set of 0.002" undersized balls that EMPI sells for the 930 CVs, which I think are already in these CVs after playing with them for a while. Not sloppy loose, but the cage definitely moves around easier.
_________________
'86 Syncro CHC Top AAZ Turbodiesel
'04 Passat Variant 4Mo 5MT

Vanagon Build: http://www.thesamba.com/vw/forum/viewtopic.php?t=466866&highlight=

[syncrodoka]

yes, I know that this is what race shops do to improve the CVs(race prep). Is there and down side to doing this to the CVs? Will I be sacrificing service life for better action or is it now a better CV joint that has been relieved similar to porting/polishing a head?

[dredward]

I am going to begine rebuildinding/exchangeing parts from my van, Mainly fr sub frame, suspension, brakes, new axles, lines etc...... From what i am understanding do i have to replace my rear axles with longer ones to use the 16in arms? I will run stocker cv's for the time being. I am not doing too much hard off roading so i am not concerned with 930 cv's. I understand that the added hight of the 16 arms, springs, and shocks will max out the cv's under extreme conditions but for the time being can i run my axles to get me by while i save some $ ????

[syncrodoka]

Just the burley trailing arms with no lift or OME shocks and mostly street driven for now? You should be fine. The 930 CVs are to get more articulation when off road but you will never have that issue on the street. If I am wrong you can come over and tell me so

[dredward]

[syncrodoka]

It looks like I got the wrong tranny drive flanges. After pulling the entire rear end apart I went to reinstall everything and the flanges won't fit.
I will have to try again next weekend- Dang.

[SyncroGhia]

Important discovery

I found my aftermarket 108mm output flanges and have just put them next to factory Syncro 16 output flanges.

The photos speak for themselves.

Sorry once again for the large images.

This would account for some of the difference in driveshaft length of the Syncro 16 having shorter shafts than Syncro 14s. Unfortunately, I don't have a Syncro 14/2WD output flange to hand to put against these but I do have a front diff in the garage at present so that might change soon.

From what I've measured, the Syncro flange is 6mm taller overall than the aftermarket flange. 1mm of that is a deeper lip that the CV joint sits into and the other 5mm is overall length so this should be taken into account when working out driveshaft length.

MG
_________________
T3 Syncro 16 S6 Westfalia Limey SOLD
T3 Syncro 6x6 SOLD
T3 RS6 Bluestar
T3 Tristar Syncro 16 SOLD
T3 Tristar Syncro RHD SOLD

[SyncroGhia]