CV Joints - ALL Tech and Specs

[AgitatedPancake]

Alright from what I recall we don't have a proper thread specifically for CVs, we've just had some good conversations in the middle of other threads. So let's do this thing.

Let's collect data on basically EVERY single CV we find, even if they're irrelevant to our specific wheeling needs. Everything from bolt on CVs, to OEM style CV stub shafts, driveshaft CVs, toyota birfields, you name it. Also interesting technology people are exploring like fancy plunging axle shafts so fixed CVs can be run

Critical dimensions:

Outside diameter of bell
Width/Thickness
Max Angle
Bolt circle (if applicable)
Bolt size (if applicable)
Ball bearing diameter
Internal splines
External splines (stub shaft bells).

To start, some links to previous discussions:

The IFS 101 thread has a good conversation starting around post #300 (and is a solid thread worth a skim anyways)
Ifs 101

The Future of 4400 thread is solid as well, and has some good CV talks starting around post #450 (and I'm sure other spots I can't recall)
Future of KOH 4400 chassis/car development?

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So let's start with sizing. We commonly refer to them by their Porsche designation like 930 and 934, but there is a more useful standardized naming scheme for most variants that is just "Size XX" or "Series XX". If there are other standards out there, let's learn about them. Note, there are a lot of blank spaces and question marks below, if you can help me fill them in, by all means!

Starting from small to large:


Size 10 - Bolt On
94mm OD
32mm Wide
__° (?) Max angle
Plunging +/- 8mm
Bolt Pattern - 6 x __mm
Bolt Holes - 8mm
Ball Bearing Diameter - ___
Internal Splines: 33 (fine pitch, 32DP?)


Size 12 - Bolt On ("Bus" CVs, or Type 4's)
100mm OD
32mm Wide
__° (?) Max angle
Plunging +/- 8mm
Bolt Pattern - 6 x __mm
Bolt Holes - 8mm
Ball Bearing Diameter - ___
Internal Splines: 25 Spline (24/48 DP with 30 degree pressure angle?)


Size 15 - Bolt On ("930" Joint)
108mm OD
32mm Wide
Fixed - Optional
Fixed Angle - 45°?
Plunging +/- 14mm
Plunging Angle - 25°
Bolt Pattern - 6 x __mm
Bolt Holes - 10mm
Ball Bearing Diameter - 1" (RCV and Empi) and 0.875" (GKN?)
Internal Splines: 28 or 30 splines (24/48 DP with 30 degree pressure angle)


Size 18 - Bolt On
115mm OD
30.5mm Wide
__° (?) Max angle
Plunging +/- 8mm
Bolt Pattern - 6 x __mm
Bolt Holes - 12mm
Ball Bearing Diameter - ___
Internal Splines: 30 splines (24/48 DP with 30 degree pressure angle?)


Size 21 - Bolt On ("934" Joint)
128mm OD
46mm Wide
Fixed - Optional
Fixed Angle - 45°?
Plunging +/- 12mm
Plunging Angle - 28°?
Bolt Pattern - 6 x 108mm
Bolt Holes - 12mm
Ball Bearing Diameter - 1" (RCV and Empi)
Internal Splines: 33 or 35 spline (24/48 DP with 30 degree pressure angle)


Size 30 - Bolt On
148mm OD
48mm Wide
Fixed - Optional
Fixed Angle - 45°?
Plunging +/- 12mm
Plunging Angle - 28°?
Bolt Pattern - 6 x 128mm
Bolt Holes - 12mm
Ball Bearing Diameter - 1" (RCV and Empi)
Internal Splines: 33, 35, 40, 47 spline (24/48 DP with 30 degree pressure angle)

 

[AgitatedPancake]

So the first post focused on the bolt on solutions. This reply let's focus on integrated CVs, where the CV bell is part of a one piece stub shaft. Outer joints are usually fixed, and inners are some variant of plunging joint (standard ball bearing, tripod, etc)

Not nearly as much starting info here, but let's collect what you have. I'll sort it somewhat small to large like the above post.

Dana 30 CV - Generic
85mm OD / 3.375"
Fixed
Max Angle - 45°
Stub Splines - 27 (24/48 DP with 30 degree pressure angle)
Internal Splines - 32 (32 DP? roughly 1.05" spline OD)
Ball Bearing Diameter - 21/32


Toyota "Birfield" CV (Mini truck)
?? OD
Fixed
Max Angle - ??
Stub Splines - 30
Internal (Star) Splines - 27
Ball Bearing Diameter - ??


Toyota "Birfield" CV ( Large Land Cruiser)
?? OD
Fixed
Max Angle - ??
Stub Splines - 30
Internal Splines - 30(?)
Ball Bearing Diameter - ??

Super Duty 60 - 99-04
4.375" OD
Fixed
Max Angle - 45° ?
Stub Splines - 35
Internal (Star) Splines - 35
Ball Bearing Diameter - ??


And let's see more! GM IFS inners and outers, Ford expedition IRS inners and outers, muscle car rear inners and outers, whatever ya got. I would like to know if these "integrated" CVs follow any of the same standards as the above "Size XX" system, or if there's a different system, or if it changes for every vehicle in existence .

 

[AgitatedPancake]

This third post we'll just keep for some useful references and media

RCV makes all sorts of quality CV joints and axle shaft kits:
RCV Performance - Ultimate CV Axles

Kartek has a decent selection of Empi and GKN components:
CV Joint Assemblies - Kartek Off-Road

Race-Parts has various levels of GKN components:
GKN Motorsport Constant Velocity Joints - race-parts.com


RCV Has a cool chart for understanding their offerings:

 

[AgitatedPancake]

And this final post will be about some unique concepts/products that may help advance the industry. The most pivotal thing I want to see more of are more "ball spline" telescoping axle shafts. Super low friction plunging, even under high loads. And it allows you to run fixed CV joints on both ends. Besides having a huge amount of extra angle available on the inboard joint, I wonder how much cooler a fixed joint would run there than a plunging joint.

This GKN article displays a ball spline setup, as well as talking about some innovation in the CV joints themselves:

Rethinking Constant Velocity Joints | GKN technology 2016 | GKN Automotive

Nexteer example:

Undercut Free / Ball Spline Axle / Undercut Free - Nexteer



TrakMotive produces and sells their own version as "Xtended Travel" shafts. I believe Napa has a very similar (or rebranded) product line as well. These are priced pretty competitively, but from what I've seen online there are questions about quality. I believe JNHEscher may have some experience with their Subaru variant IIRC?



Napa's Extended Travel variant:

 

[fl0w3n]

Cool idea. I have a set of D30 RCVs and some D60 RCVs I can pull measurements on.

I am also in the process of researching if there’s a difference in the CV itself between “new” D44 and D30, or if it’s just spline and length difference.

 

[AgitatedPancake]

Cool idea. I have a set of D30 RCVs and some D60 RCVs I can pull measurements on.

I am also in the process of researching if there’s a difference in the CV itself between “new” D44 and D30, or if it’s just spline and length difference.

That would be sweet. At one point I heard the regular D60 RCVs were 934 (size 21) equivalents, and the "big bell" rockwell and 05+ 60 shafts were size 30 based. Be curious how true that ends up being.

 

[fl0w3n]

That would be sweet. At one point I heard the regular D60 RCVs were 934 (size 21) equivalents, and the "big bell" rockwell and 05+ 60 shafts were size 30 based. Be curious how true that ends up being.

Does the integrated CV reference over just like that? Are ball/cage/housing strengths all the same between the two, with the difference being bolt on or integrated stub shaft?

I’ve always wondered how strengths compare to standard shafts.

If strength goes weakest to strongest series 15/21/30, with presumably increasing strength within series as spline increases, where would 1480 and 1550 fit into that chart? I know there’s lots of variables so probably unlikely to find a straight up answer

 

[AgitatedPancake]

Does the integrated CV reference over just like that? Are ball/cage/housing strengths all the same between the two, with the difference being bolt on or integrated stub shaft?

I honestly have no clue yet, but definitely hope to learn here. In OEM form I think there's a high chance of having all sorts of varied solutions. I hope not, but wouldn't be surprised. But as far as aftermarket like RCV is concerned, I think there's a good chance they reused the ball bearings, cages, and stars between the bolt on and integrated products.

 

[bdkw1]

Series 12 are also type 4 or buss CV's. They also show up on a lot of other FWD euro cars.

 

[AgitatedPancake]

Good note, added.

I wish I still had some of my old jeep CV front driveshafts kicking around, really curious if those stack up against common sizes.

I also recently found out the latest handful of Camaros use bolt on size 18 CVs at the dif. Thought that was interesting, I wasn't even familiar with the size until recently

 

[Pharr]

934 are bolt pattern - 6 x 108mm

RCV makes bolt on and integrated that are designed to work with Spidertrax's unit bearings.

The star and cage are what gives most of the angle capability. In RCVs integrated type 934 it's 40° max. I can take some measurements and pictures. I'm running GKN inner an RCV outers, all 35 spline series 934.

There's also differences in axle retention, i.e., where the snap ring is located.

 

[Pharr]

Are ball/cage/housing strengths all the same between the two, with the difference being bolt on or integrated stub shaft?

It's more complicated than that. Material choice, cage shape (longer slots gives more angle but is weaker) and size play a part in strength and angle capability. Loren Healy was initially running 934 on the front of his 4400 to save weight because he didn't need the strength of the 30 thanks to the great reduction of portals. He had to change to the 30 series because he was popping them out at full flex.

 

[Pharr]

unique concepts/products

Tripode joints:

GKN Motorsport Tripode Joints & Housings - raceparts.com

Buy your GKN Motorsport Tripode Joints and Accessories from us at Raceparts USA, the right parts right here online, order with experienced advice and delivery.

www.race-parts.com

Road racing Miatas use these and there's a neat lightweight, serviceable version:

Tripod Joint Housing - Aluminum, 94mm Dia, 40mm Thick | Pegasus Auto Racing Supplies

This anodized billet aluminum tripod joint housing fits most FF1600 and FF2000 Van Diemen from 1990 to 1999.

www.pegasusautoracing.com

I considered it for my driveshafts. They are stronger than CVs of equivalent size but I can't find any larger than 26 splines, so I don't think they would be strong enough.

 

[[486]]

Series 12 are also type 4 or buss CV's. They also show up on a lot of other FWD euro cars.

yup, they're on 99-05 VW A-chassis cars with the lower powered engines, in plunging format
got a different spline inside them than the bus joints, too, a 33spl which is about 1" minor, 1.05" major diameter

 

[AgitatedPancake]

934 are bolt pattern - 6 x 108mm

RCV makes bolt on and integrated that are designed to work with Spidertrax's unit bearings.

The star and cage are what gives most of the angle capability. In RCVs integrated type 934 it's 40° max. I can take some measurements and pictures. I'm running GKN inner an RCV outers, all 35 spline series 934.

There's also differences in axle retention, i.e., where the snap ring is located.

Thanks, added.

Very interesting on the 934 integrated maxing at 40°, I thought (but don't have personal experience) that their standard D60 CV's could reach 45°. And was that the variant you mentioned for the spidertrax unit bearing? Is that the same as the 99-04 super duty stub?

Very interesting on Loren's scenario as well, I'm pretty surprised to hear he had to step up to a size 30 upstream of the portal reduction. He was popping them out as in pulling the axle shaft out of the star?

I hadn't seen the aluminum sleeved tripod housings before, that's super cool. And a bit surprised to hear they're stronger than CVs, gives me something to read more on.

yup, they're on 99-05 VW A-chassis cars with the lower powered engines, in plunging format
got a different spline inside them than the bus joints, too, a 33spl which is about 1" minor, 1.05" major diameter

I've got to go recount the splines in the star of the D30 joint I took apart, I swear it was 32 splines but it's dimensionally way too similar to that 33 spline of the size 12. Man that's a small joint hah

 

[fl0w3n]

I've got to go recount the splines in the star of the D30 joint I took apart, I swear it was 32 splines but it's dimensionally way too similar to that 33 spline of the size 12. Man that's a small joint hah

Shouldn’t D30 be either 27 or 30?

 

[AgitatedPancake]

Shouldn’t D30 be either 27 or 30?

The splines are 27 at the diff and the stub shaft. But the star in the CV, the one I pulled apart necks WAY down to those tiny dimensions.

 

[fl0w3n]

The splines are 27 at the diff and the stub shaft. But the star in the CV, the one I pulled apart necks WAY down to those tiny dimensions.

Oh I missed that. What’s DP?

I’ve been meaning to suggest it, in your spline pressure angle thread it would be nice to see major and minor shaft diameter.

I have 27 spline d30 RCVs and I’m looking at building a junkyard 309 out of it and wondering if it makes sense to do ford 31 or 28 spline at the diff. If the spline at the star really is that small, 31 probably would be mismatched

 

[AgitatedPancake]

Oh I missed that. What’s DP?

I’ve been meaning to suggest it, in your spline pressure angle thread it would be nice to see major and minor shaft diameter.

I have 27 spline d30 RCVs and I’m looking at building a junkyard 309 out of it and wondering if it makes sense to do ford 31 or 28 spline at the diff. If the spline at the star really is that small, 31 probably would be mismatched

Diametral pitch - how many teeth per inch of shaft diameter (at the pitch circle). Most normal splines we encounter are 24 diametral pitch, so a shaft with a ~1" pitch diameter have 24 splines.

Good call on the spline thread, I'll bump that one to get the actual diameters in there as well. I might as well add a link to that thread just because of how it relates.

I'd be very curious what you end up seeing on the RCV D30 stuff, my guess is they upsized everything over this generic autoparts version I have on the bench. If their inner shafts are straight through (27 on both ends, or 30 on both ends), that alone would be a huge step up in strength over what I have here. But the way this one is designed, the star is too small to run a shaft any larger than what's in there (wall thickness gets pretty thin).

I'm all for hybrid 9" builds, but a 309 seems like an odd one haha. Just in having a diff that is far more capable than the shafts can handle. From what I've gathered, JK HP30s with 30 spline inners and 32 spline outers are pretty strong if you beef the housings up to survive, then in the worst case stepping up to the rubicon HP44

 

[[486]]

I've got to go recount the splines in the star of the D30 joint I took apart, I swear it was 32 splines but it's dimensionally way too similar to that 33 spline of the size 12. Man that's a small joint hah

if you want a spline to be compatible
it won't be

sometimes only because of a couple thousandths of excessive clearance (looking at you ZF5HP center diff into 4t65e)

 

[fl0w3n]

Diametral pitch - how many teeth per inch of shaft diameter (at the pitch circle). Most normal splines we encounter are 24 diametral pitch, so a shaft with a ~1" pitch diameter have 24 splines.

Good call on the spline thread, I'll bump that one to get the actual diameters in there as well. I might as well add a link to that thread just because of how it relates.

Good info

I'd be very curious what you end up seeing on the RCV D30 stuff, my guess is they upsized everything over this generic autoparts version I have on the bench. If their inner shafts are straight through (27 on both ends, or 30 on both ends), that alone would be a huge step up in strength over what I have here. But the way this one is designed, the star is too small to run a shaft any larger than what's in there (wall thickness gets pretty thin).

This is as far as I got last time I had the shafts out, I can’t imagine it significantly necks down after the boot seal surface

I'm all for hybrid 9" builds, but a 309 seems like an odd one haha. Just in having a diff that is far more capable than the shafts can handle. From what I've gathered, JK HP30s with 30 spline inners and 32 spline outers are pretty strong if you beef the housings up to survive, then in the worst case stepping up to the rubicon HP44

Hence my earlier comment and interest in this thread, I’m not sure if there’s a difference in the bell size between 30 and 44. If there is I’d stuff it with 44 size shafts.

 

[Pharr]

And was that the variant you mentioned for the spidertrax unit bearing? Is that the same as the 99-04 super duty stub?I

I think you could probably get 45° out of it, but not with a lot of torque applied.

I was referring to his one:

https://www.rcvperformance.com/rcv-ultimate-35-spline-cv-joint-for-spidertrax-ultimate-unit-bearings.html

He was popping them out as in pulling the axle shaft out of the star?

Yeah it wasn't a strength thing, it was an angle thing. The problem was in the whoops. He said he has to redo the whole mount and housing and everything because it was so tight and designed for the smaller 934, it didn't have the clearance for the 30.

hadn't seen the aluminum sleeved tripod housings before, that's super cool. And a bit surprised to hear they're stronger than CVs,St

Stronger, however, they can't flex as much but they have more plunge. This is why you see them on the inners on most OEM applications. They don't need to steer, the outers do.

 

[JNHEscher]

Didn't see a tag in this until this morning.

I've got some piles of OE Subaru and Toyota on hand along with aftermarket of each. I had at one point began making CAD files of Toyota CV's.

Gonna be a few days before I can provide much. No indoor workplace and it's currently 2°F

 

[benw]

Stock Toyota birfields have a 27 spline star. The 30 spline star is an aftermarket birf thing.

 

[Isdtbower]

GREAT LIST!

It has been a long time since putting in the "work" to figure out the modern 4400 IFS conundrum. 10 years ago, there was not much we could work with. (Shannon won in 2011) CV's were "stock" but RCV was willing to learn the next level in 45*+ turning angles. This was on series 30 size/35 spline joints for the outers in the uprights. To start, the balls literally fell out of the cups and 35 spline was the largest star before breaking...AND, if you could find a boot that would also allow it. Most stayed out of this rare air testing and design. Limiting turning to less than 40* and allowing the straight axle guys to make some time back up in the rocks. Inner 30 CV's would last a year and outers replaced almost very event. Jason Scherer worked every angle with several machine shops, willing fabricators, and manufacturers that wanted to develop new products. This continually challenged the Lund Family to make changes in the design and geometry of their basic IFS as limits were found and changes in what Jason wanted the tire to do. .

The desert guys had found the CV heat limit at about 25* and strangely (or not) the camber and caster geometry starts to quickly turn to trash. Do the work and you will easily see it. Compromises were huge until narrower diffs and forged, positive off set wheels came about...lengthening the shafts but still staying close to those original CV limits..Doing the work enabled eliminating plunge and became a reality and design criteria. Gotta do the work. Thom at SpirderTrax was a willing listener and learner during all of this. Dallas spent Days/Weeks making changes at the inner A-Arm mounts and upright. Running the simulations and checking the numbers against the geometry that was thought best. Luckily, the HP numbers were below the 700 mark, and transmissions couldn't take much more either.

That early CV work led the way to the SXS articulation development. Fortin was not making series 30 CV's but are now, as are others with 5 axis grinders. Amazing.

Time to include a little more info than just the basic "sizes." I know my GKN series 30 balls will not fit in a Series 30 RCV. There are differences if you want to be in the top 10 combatants.

>>>>>>>>>>>>

Geometry changes what the CV sees. But geometry depends on your driver. If your driver broad-slides, like short track. The IFS does not need to turn sharp and the camber curve can be much less aggressive. (Until that aw-shit) If you depend on the front wheels turning and pointing your direction (usually safer) then the CV's will become a thing....KOH has changed over the years. Early they "crawled the rocks" now they "skid them" without turning so much....with 40 spline shafts...portals..

There might be no wrongs. My choice for a 500hp recreational FIS is 935 except series 30/35spline in the front outer to turn max. I believe the FIS days are numbered unless similar to the high clearance Thompson Dog Bone center. G-outs and back injuries.... Straight rear axle with offset diffs for the rocks at least. Just some notes as you consider your build and choices. A lot can be said for the mechanical linkages in a IFS but All Hydro has come a long way to keep the SA's competitive and a challenge for electric steering. Always more to follow.

CV's are NOT constant. There is "some" loping and loss of strength at angles At one time GKN did publish that but can't find it anymore. All of that could have been really heat un-related. (Ditched so to not entice an "engineer" at large constant angles. )

 

[snivilous]

The telescoping shaft CVs are cool, I didn't know about them until recently. This one for a Toyota Tundra from Rock Auto a friend sent me pulls 48deg on both sides and has 3" of plunge as I recall. It's very cool since the tripod inner design has the issue that you get angle or you get plunge, not both. Granted you can remove plunge with geometry design, but the 6 ball style on both ends help alleviate that constraint. Not sure how they'll hold up being pushed to the limit, but I'm able to pull 18" of travel in a bolt in application without maxing the joint out at full droop/lock which is wild for an off the shelf axle.

 

[Isdtbower]

The telescoping shaft CVs are cool, I didn't know about them until recently. This one for a Toyota Tundra from Rock Auto a friend sent me pulls 48deg on both sides and has 3" of plunge as I recall. It's very cool since the tripod inner design has the issue that you get angle or you get plunge, not both. Granted you can remove plunge with geometry design, but the 6 ball style on both ends help alleviate that constraint. Not sure how they'll hold up being pushed to the limit, but I'm able to pull 18" of travel in a bolt in application without maxing the joint out at full droop/lock which is wild for an off the shelf axle.

>>>>>>>>>>>>>>>>

The ball plunge shaft is not new. I looked at that before 2000 for a IRS because I didn't know how to design for "no plunge." Then the desert guys tried it with mixed results. Usually HP and heat related. Some even attached fan-like blades to the the shafts to scrub heat. Recreationally, I didn't think it as a problem.

As a FYI. I have built three IRS set=ups using a Corvette model 44 aluminum center with U-joints and solid half shafts. We let the shafts plunge into the differential. One is going on 58 years with no problems or leaks. 2000lb Flat fender, 400hp SBC and sand tires. Articulation is about 8"...OLd school. coil-over. I don't plan on using plunging CV's on a 9" IFS pumpkin. I wouldn't hesitate to do it again for less than 1/2" plunge. The 9" centers can-be/are built to do that. You just have to think out the main diff bearings for a slight amount of misalignment. Nothing is zero plunge in life.....

Apparently non plungng CVs are stronger than plunging. More options..

 

[arse_sidewards]

TrakMotive produces and sells their own version as "Xtended Travel" shafts. I believe Napa has a very similar (or rebranded) product line as well. These are priced pretty competitively, but from what I've seen online there are questions about quality. I believe JNHEscher may have some experience with their Subaru variant IIRC?

I have a bunch in my fleet.

My annual CV killing problem went away.

 

[arse_sidewards]

The ball plunge shaft is not new. I looked at that before 2000 for a IRS because I didn't know how to design for "no plunge." Then the desert guys tried it with mixed results. Usually HP and heat related. Some even attached fan-like blades to the the shafts to scrub heat. Recreationally, I didn't think it as a problem.

As a FYI. I have built three IRS set=ups using a Corvette model 44 aluminum center with U-joints and solid half shafts. We let the shafts plunge into the differential. One is going on 58 years with no problems or leaks. 2000lb Flat fender, 400hp SBC and sand tires. Articulation is about 8"...OLd school. coil-over. I don't plan on using plunging CV's on a 9" IFS pumpkin. I wouldn't hesitate to do it again for less than 1/2" plunge. The 9" centers can-be/are built to do that. You just have to think out the main diff bearings for a slight amount of misalignment. Nothing is zero plunge in life.....

Apparently non plungng CVs are stronger than plunging. More options..

Zero plunge = wreck other shit when a joint end or bushing gets worn out.

 

[AgitatedPancake]

Awesome stuff guys. I'll add the note on the 27 spline star in the Toyota birf, good note.

Pharr - thanks for the link to that stub, So now I'm a little more intrigued, I thought the ultimates might have been 99-04 super duty equivalents but doesn't seem to be the case (at least that specific stub shifting the CV pivot outward a bit). I knew Spidertrax had their super shorty setup, but that seems to be yet another solution



Ben - great comments as always, gives some insight into the "recent" history of CV evolution. And your second post brings up something I've always wondered about but there isn't enough discussion out there - how much can you let shaft splines plunge if you want to run fixed joints on both ends? Based on your experiences, sounds like there's a good amount of wiggle room there! Have you seen any noteworthy degredation of the male or female splines that are plunging?

snivilous - Awesome. Just for clarity, that shaft in your pics is one of the ball spline extended travel deals? The cool thing is they offer those for so many larger truck applications, we may find some with common splines and/or mounting configurations to be used more readily.

arse - around how many miles have you put on them? I saw a few videos that seemed to be early failures, but I don't actually know what failed, just that people swapped them back out for traditional shafts with tripod joints. But that could have been user error, I want to believe haha.