RCR CV Joint Dimensions

[Jason Ferraro]

Not much luck in getting detailed replies to emails from RCR for the last few weeks. I'm wondering if a current RCR owner can help.
I'm trying to move my engine as far forward as I can and would like to know if someone can tell me the dimensions of the CV joint on the STD drive shafts supplied by RCR. I have had them on order for a while and I'm really not sure when they will be sent but would like to position the engine before they turn up. The diameter and "thickness" as shown in the image below would be a great help to me. Thanks in advance.

 

[Fran Hall RCR]

Jason,
I have been replying to everyone of your emails....

I need dimensions from you as your want to move your engine as far forward as possible the amount of plunge on the axles is finite...

I said this in at least a couple of emails to you..this may have had something to do with it too.
http://www.gt40s.com/forum/rcr-forum-rcr40-rcr70-p4-mkiv/25864-mailbox.html

Call me or PM me on here as I get those messages daily

 

[Randy V]

Check out the link below to my website as it has some of the information / pictures you are looking for Jason. If you have any other questions I'd be happy to try and help as well.

Driveline:
GT-Forty.com

 

[Old Roaring Forties]

Not much luck in getting detailed replies to emails from RCR for the last few weeks. I'm wondering if a current RCR owner can help.
I'm trying to move my engine as far forward as I can and would like to know if someone can tell me the dimensions of the CV joint on the STD drive shafts supplied by RCR. I have had them on order for a while and I'm really not sure when they will be sent but would like to position the engine before they turn up. The diameter and "thickness" as shown in the image below would be a great help to me. Thanks in advance.

Hi Jason,

I'm sure they are Porsche / Commodore (and various other manufacturers use them) CV's, I have some you can use to set up the trans / eng before your axels arrive ?

There are 2 versions with slight differences in spline length only, this may account for the 2 vs 1 circlip attachment on bogfoots axels - we have had to do the same with new old stock parts.

Regards Paul

 

[roaldin]

Fran,

I've had trouble with email getting to/from you in the past. Maybe a spam filter or similar is getting in the way?

Apologies if I'm off track.

Tim.

 

[Fran Hall RCR]

I just relaxed the filtering and dont seem to be having any issues at the moment...

So hopefully things are back on track....please resend anything I may have not replied to....thanks

I know when sending emails out some Companies dont accept Yahoo/gmail incoming ...

I know email is great but we all take it for granted that everything works 100% of the time....if only!

 

[Jason Ferraro]

Received my 12.5" long drive shafts originally purchased from RCR last week (supplier was very helpful in sending corrected length shafts). Just fitting them at the moment and shaft length is now good (13.5" was too long), outer CV bolts up fine but the inner CV will not fit to my Ricardo transaxle output flange. I believe the RCR stub axle bolt circle diameter is 94mm and a 10mm bolt is used (108mm OD CV joint), BUT the Ricardo output flange bolt circle diameter must be different! I did not specify this with the supplier as they were originally ordered a year ago with my car from RCR.

Does anyone know what a Ricardo output flange bolt circle is? I measure it to be ~95.75mm. The 10mm bolt fits in one hole but it looks like the bolt circle diameter is NOT 94mm (its slightly larger). Looks like a different bolt circle diameter is required, I may be wrong?

Help from anyone would be great as if the outer race is not correct on one end of the shaft I do not know what to do.

 

[jyrki sulka]

If bolt circle is few mm`s more You have two option:

1) take out "stumps" from box and lathe (mark new circle) and drill + make new threads for CV bolts. Only if there is enough material (and shape) to do that.

2) buy new inner CV joints, GT originals or similar, where is right bolt circle to "stump" AND splines to saft.

 

[Cliff Beer]

Jason, what make are your CVs? Lobro?

There are a few CV rebuild/repair facilities of some size/scope around that can help you find and fit an inner CV that works with your Ricardo transaxle. Take a look at google for starters. You can also try contacting Lobro directly.

The splined end of the axle is somewhat common to a range of different CV joints - at least that's the way it is for Lobro. So, that means you have a fair chance of finding an inner CV that is compatible (same bolt pattern and OD). If not, then, my reco would be to find the largest CV that fits on your axle splines and then have the CV joint turned down on the lathe and the bolt pattern drilled with an indexed rotary table on a mill.

 

[Jason Ferraro]

Thanks for the comments.

They are from the "drive shaft shop" in the USA. As they were ordered for this exact installation I will try to get some info from RCR on Monday. Just wondered whether the Ricardo bolt center radius I measured was standard? If it is not the only option I can see to use the CV's I have would be to have the existing holes elongated about 0.8mm radially (in a milling machine with an indexing head. It will only leave 1mm at the edge of the hole and CV outer but this may not be a problem. Or drill another 6 holes in the CV, but I will try to get some that should fit the application they were ordered for. It may be VERY hard to drill them. I hope I'm not doing something wrong!

Others have had CVs from RCR for Ricardo's so I hope they have some suggestions.

 

[Fran Hall RCR]

Unfortunately some of the Ford stub axles are machined with very slack tolerances...

We have some that bolt up directly and others that have required we chase the threads ...in one case we just slightyly over drilled the inboard CV joint and everything bolted together...but take your time installing the bolts and be careful not to damage the threads... .

My SL-C is the car we did this to and it is functioning just fine...having been beaten on by some other Aussie on track for 350 miles...

If you look carefully at the Ford/Ricardo forging you may see that the holes are drilled off center to the bosses ....bad QC but still fully functional

There are only a few industry standard CV bolt circles and the Ford GT uses the same as the Porsche 930 (RCR stub axles also use this dimension)...in fact the Ford GT clutch/flywheel assembly mimics the whole Porsche assembly very closely...

 

[Magnus]

Hello!
I have the same problem. I measure it to 96mm. I show some picture of my driveshaft place.
Where is the best place to bay cv and drivshaft to my car?
I have more building picture here. Picasa Web Albums - Magnus

 

[Jim Rosenthal]

I think the standard "Porsche 930" type CV joint is a 94 mm bolt circle. You might try "GForce" in Kansas City, MO; they make a lot of high-performance halfshafts and are familiar with these. There is also an even higher-performance CV joint they call a "934" joint- maybe this takes a slightly bigger bolt circle.

Most "Porsche 930" CV joints are not made by Porsche at all; this seems to be a standard dimension that was settled upon a few years back and a lot of companies use it. My ZF transaxle has that output flange (94mm, with 10mm bolts, I think) and those transaxles came in BMWs, Maseratis, DeTomasos, and probably other cars I don't know about.

 

[Fran Hall RCR]

Jim,

the 930 CV is actually described as 108mm as I mentioned earlier.
The Ford GT is the same....
The dimension is not listed from hole to hole centerline but overall OD.

www.driveshaftshop.com is the supplier I use...

 

[Lynn Erickson]

Jim,

the 930 CV is actually described as 108mm as I mentioned earlier.
The Ford GT is the same....
The dimension is not listed from hole to hole centerline but overall OD.

www.driveshaftshop.com is the supplier I use...

I just tried a 930 cv on my ricardo flange and it does not fit. on my Porsche buggy trans the cv fits into a recess on the drive hub. are there any pics of the stock ford drive shaft on the trans end. does the stock cv fit into the internal bore of the ricardo drive flange? it does not seem right to just bolt up to the flange with no way to center the 930 cv except the bolts.

 

[Fran Hall RCR]

I will post a pic of how the 930 dimensioned CV fits onto the Ricardo....as mentioned I use driveshaftshop CV's as part of the custom axle assembly..not stock Porsche CV's...not that it should make any difference

The Ford inner CV becomes more problematic when you have the Factory Ford inner flange badly machined as shown in a previous picture by Magnus...

 

[Jim Rosenthal]

Got it. Am I right that "Porsche 930" is sort of a generic term like "Xerox" and doesn't necessarily refer to a Porsche product, just the same size etc? My 930 joints and boots appear to have been made by GKM. I think the axles may have come from DSS as well. I'm not sure who Safir use as a supplier, but there aren't a lot of companies making these.

 

[Fran Hall RCR]

I checked on the Ford GT and there is no centering/alignment provision..the six bolts do all the work...

 

[Fran Hall RCR]

and the CV is listed as 108mm....(stock Porsche 928/930 fits fine..)

 

[Lynn Erickson]

I checked on the Ford GT and there is no centering/alignment provision..the six bolts do all the work...

thanks for the information. I tried the ones off my porsche trans and they do not fit the bolt pattern on the ricardo it is a bit bigger then the porsche.