Double Cardan Vs. Cv Drive Shaft - Page 2

**mdm** · 09-30-2009, 08:16 AM

Quote:

Originally Posted by PeteYJTJ

I'm not a JK guy, but don't JKs have CV joint (ball type) rear driveshafts, rather than ujoints? I thought I saw that somewhere.

Pete

Don't think so. Most in the Jeep community use the terms double cardan and CV to mean the same thing. They are really refering to the double cardan style shaft with two u-joints and a centering ball on the transfer case end and a single u-joint on the differential end.

PeteYJTJ · 09-30-2009, 08:24 AM

2007 Jeep Wrangler JK Driveshaft - 4 Wheel Drive and Sport Utility Magazine

?????

Pete

MeltdWhiskey · 09-30-2009, 08:27 AM

if i ever have to install another ds, i'm going with Cornay. i assume price has something to do with me not hearing much about them on any of the forums.

Cornay® - Welcome

**mdm** · 09-30-2009, 08:32 AM

Quote:

Originally Posted by PeteYJTJ

2007 Jeep Wrangler JK Driveshaft - 4 Wheel Drive and Sport Utility Magazine

?????

Pete

You were right. Hmm! I had crawled around under on and didn't notice it. I was paying more attention to the suspension and obviously didn't pay enough attention to the drive shaft.

PeteYJTJ · 09-30-2009, 08:42 AM

Like I said -- I didn't remember, had to go find that. Maybe they've stopped using them, as it was considered a weak point? I have no idea. Man, JK's been in production almost 4 years already. Yikes, time flies!

Pete

**mdm** · 09-30-2009, 08:49 AM

Quote:

Originally Posted by PeteYJTJ

...Man, JK's been in production almost 4 years already. Yikes, time flies!...

It was right after the JK hit the dealer lots that I was crawling around under one and I can barely remember what I had for dinner last night. Did I have dinner last night?

lukethedork · 09-30-2009, 09:31 AM

Quote:

Originally Posted by dippert

constant velocity (CV) joint

works like this

a double cardan uses U-joints instead of that weird ball thingy those toyota ppl are so fond of (front axle)

I don't know what you define a 'CV' joint as. But to me it is a Constant Velocity joint and much like a TV (television) it can come in many different shapes, sizes, and designs.

I believe the joint in the pictures you posted is called a Rzeppa joint.
Both the Rzeppa joint and Double-Cardan joint are what I consider to be CV joints.

Luke.

**mike_dippert** · 09-30-2009, 09:56 AM

Quote:

Originally Posted by MeltdWhiskey

if i ever have to install another ds, i'm going with Cornay. i assume price has something to do with me not hearing much about them on any of the forums.
They list a maximum and operating RPM's. operating RPM of their CVX joint is only 2200, but maximum is 5000. Might want to ask them what would happen if you drive for sustained periods over 2200 RPM. Even w/ my OD (0.72ish:1) i still go over 2200 RPM on the highway.

Cornay® - Welcome

Quote:

Originally Posted by lukethedork

I don't know what you define a 'CV' joint as. But to me it is a Constant Velocity joint and much like a TV (television) it can come in many different shapes, sizes, and designs.

I believe the joint in the pictures you posted is called a Rzeppa joint.
Both the Rzeppa joint and Double-Cardan joint are what I consider to be CV joints.

Luke.

DC, Rzeppa (which i posted animations of), Tripod, Thompson couplings. They are all CV joints of varying sorts. A lot of car people think of Rzeppa styles when we say 'CV' joint. Is that a Rzeppa on the stock JK?
If you feel the need to jump on me about this, why don't you call them what they really are? Rzeppa and DC joints. Just calling it a CV might confuse somebody. Obviously the OP was confused about the difference.

Double Cardan Joint

Rzeppa Joint

Tripod Joint

Thompson Coupling
[yt]Dh5C4e4exhM[/yt]

**Jerry Bransford** · 09-30-2009, 10:14 AM

This is an old thread but since it has been revived, driveshaft expert Tom Wood considers a double-Cardan and a CV joint to be the same thing. His opinion is good enough for me and I'll continue to use the terms interchangeably.

In all of his technical writeups, Tom uses the two terms interchangeably and even places one in parenthesis following the other like where he says "The real benefit to a C. V. (double cardan) drive shaft is smoother operation at higher operating angles and longer life. The C.V. assembly works by intersecting the joint angles at the center pivot point and delivering a smooth rotational power flow or surface velocity through the drive line." at Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist on his Driveline Geometry 101 tech page.

That above animation is cool but that's not the only form of CV joint, the driveshaft industry widely categorizes a double-Cardan (two u-joints with a centering joint) and many other types as a CV (constant velocity) style joints as well.

**Unlimited04** · 09-30-2009, 11:19 AM

Quote:

Originally Posted by dippert

DC, Rzeppa (which i posted animations of), Tripod, Thompson couplings. They are all CV joints of varying sorts. A lot of car people think of Rzeppa styles when we say 'CV' joint. Is that a Rzeppa on the stock JK?
If you feel the need to jump on me about this, why don't you call them what they really are? Rzeppa and DC joints. Just calling it a CV might confuse somebody. Obviously the OP was confused about the difference.

Double Cardan Joint

Rzeppa Joint

Tripod Joint

Thompson Coupling
[yt]Dh5C4e4exhM[/yt]

This is an awesome explanation. I'm stealing it and adding it here: http://www.jeepforum.com/forum/f9/what-cv-shaft-why-do-i-want-one-854790/index4.html

**mike_dippert** · 09-30-2009, 11:24 AM

a rectangle is a square but a square isn't a rectangle.
but for the purposes of Jeepforum, and jeeps in general, CV and DC joints are the same object. but in the world of joints, they aren't always interchangable. hence TW using parenthesis to specify which CV joint he's talking about.

**NotURMailman** · 09-30-2009, 12:30 PM

This is like DeJaVu...

They are all types of CV joints.

Double cardan type CV joint - the kind most Jeeps use on the drive shafts, utilizing two U-joints

RZeppa type CV joint - the "ball type" you usually see on front wheel drive imports

Tripod style - a plunger type, resembles a three ended u-joint inside of a machined housing (sometimes also of FWD car axles)

Birfield joint - another style of "ball type" CV joint, theses are the ones people are usually talking about when they refer to older Toyota front axle shafts

So yes, a double cardan joint is a CV joint. But no, a CV joint isn't nescessarily a double cardan joint.

So you can't ask if a DC joint or a CV joint is better. That's like asking "Which is better - oil or lubricant?"!

BTW - CV joint means constant velocity joint, meaning that it theoratically does not change speed as it rotates through it's range of motion when operated at an angle...

Zachs · 09-30-2009, 01:09 PM

^ great info man.

bean66 · 09-30-2009, 01:47 PM

Is anyone making a drive shaft with a thompson coupling?

A shaft with two couplings one on each end would pretty much allow the transfercase vs differential to be at just about any angles...
Eliminating the need to install adjustable control arms etc.

**NotURMailman** · 09-30-2009, 02:06 PM

Quote:

Originally Posted by bean66

Is anyone making a drive shaft with a thompson coupling?

A shaft with two couplings one on each end would pretty much allow the transfercase vs differential to be at just about any angles...
Eliminating the need to install adjustable control arms etc.

I doubt it, I believe that is a fairly new design...

Looks like a high tech variation of a double cardan joint.

Probably pretty expensive!