Off Roading Forums banner

Are angles suppose to be the same on a cv driveshaft?

547 Views 7 Replies 3 Participants Last post by  CJDave
G
Are the angles suppose to be the same at both ends on a cv style driveshaft?

1 - 8 of 8 Posts
3
/wwwthreads_images/icons/crazy.gif You see, drivelines with standard u-joints operate under the rule that the joint angles each end must be the same to cancel each other out. Each joint has to have a cancel-mate, or BIG vibrations occur when the joint action goes through the cycle: fast-slow-fast-slow-fast...well, you get the idea...joints do not deliver power at a constant RPM...unless they are......you guessed it....CONSTANT VELOCITY u-joints. SO.....when you install a CV joint, it is IT'S OWN cancel buddy, and needs no help from the other end of the shaft. On the other end, the standard (non-CV) joint is now all alone, with no cancel buddy, he is mad at you, so he will deliver power all crazy/wwwthreads_images/icons/crazy.gif...fast-slow-fast-slow....now that he has no other joint to help him cancel out. SOOOOO....you have to make him a ZERO ANGLE joint...so there IS no fast-slow-fast-slow...it is just like there was no joint action at all. So the setup on a mixed (CV joint and regular joint on the same driveline)driveline is....CV joint has angle...standard joint points directly toward the driveline with no angle, except for whatever you build in to allow for normal windup and loading. /wwwthreads_images/icons/wink.gif

CJDave
See less See more
G
Great explaination CJDave - very easy to understand. I've never heard it described like that.

Marc
Contagious Racing
2
/wwwthreads_images/icons/wink.gif Learnt that in engineering skool. /wwwthreads_images/icons/smile.gif

CJDave
See less See more
But CJDave, Can a C/V joint driveshaft drop as far as a convintional doubble ended U-joint shaft?

3
/wwwthreads_images/icons/tongue.gif Not likely. The CV joint is taking the angle in two steps, whereas the conventional joint is doing it in one, BUT the problem is that the movement of CV joints is restricted because they must be their own support, instead of each joint in a yolk bolted to a case...they can get downright floppy with wear. There is actually more turning room in a conventional yolk. That's where two-piece shafts have a little advantage if the angle/drop is extreme, but there is never ROOM for a two piece. Did you ever notice how the bobtails are set up? The u-joint on the tranny has zero angle, and the shaft drops out at the angle that the engine and tranny are on. Then they punch through a hangar bearing with the slip yolk on the backside to the driveline. A three-joint system, with one joint at zero./wwwthreads_images/icons/wink.gif The big problem with lots of angle on a conventional shaft is that there is so much cycle...slow-fast-slow-fast-slow-fast....that it exaggerates any little error in initial angle settings AND changes in frame-axle relationships as your 325 pound buddy hops in. It has to be perfect, and so few are. I have set up lots of equipment with big drivelines at huge angles, but the easy part was...nothing moved around....our angles stayed where we put them. THAT'S where CV joints shine, when something is changing all the time. What Jeepdom needs is the top-pinion rear axle like the trucks have./wwwthreads_images/icons/laugh.gif

CJDave
See less See more
Dave-
Your wish has been granted.
The hot new setup is a reverse cut, top pinioned 60.

JAF
3
/wwwthreads_images/icons/shocked.gif You know, I saw a third member in one of the magazines, and just stared at it trying to figure out how the front pinion bearing could possibly get oiled./wwwthreads_images/icons/tongue.gif The differential had a high pinion, with very little hypoid, a real strong setup IF you can keep it oiled. /wwwthreads_images/icons/smile.gif

CJDave
See less See more
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top