CV dShaft vs Single uJoints

ckruzer

Infidel
Joined
Jul 2, 2015
Location
asheville nc
What are yalls experience with cv (double cardon) and single ujoint driveshafts? In researching to understand the benefits of the two. It appears the only reason to go to the double cardon is if you have a super short dshaft it will alleviate your vibes, or otherwise to give you the opportunity to raise your pinion so it doesnt bang on rocks as easy.

Other than rocks - how much importance do yall put on using a double cardon dshaft like most of the aftermarket 4x4 crowd says to do?

Unless its unwise, my plan is to get a XJ front shaft cut it down to my proper size, and then just use a standard single ujoint on both ends. This will enable me to leave the perches as they are the d60 (might have to use a wedge), while also getting me on the road very very cheaply. In the future if i ever plan to do heavy trails i can much more justifiably dump the money into putting new perches on with a cv dshaft and viola!

What is your thoughts?
 
Are you trying to fix the front shaft or the rear shaft? Aren't XJ front shafts CV anyway, like the TJs?
 
Have a shaft made. The shops local to Asheville are gonna charge around a 100 to balance it. You will have to balance it to drive on the street. And you'll still have the thin wall driveshafts. A dana 60 and 37s on going to put alot of strain on a driveshaft designed to turn 28" tires, not saying it will twist it. But I just ordered a 120 wall slip yoke driveshaft with a CV joint on it and custom length for a little over 200. I would buck up do it once and be done
 
Ehhh, few years back Asheville person
Power train made me a rear shaft for a yj out of a xj front shaft. $25 to cut it, $25 to balance it. I skipped balancing, ran smooth. Since then I've cut and welded my own with good results by eye. Ymmv.
 
It also depends on the type of suspension and how it's designed.

Ex: long travel leafs, the axle tends to move up and down, and not rotate "much", keeping the pinion angle relatively constant thought travel. This is better suited to a single joint shaft.

A link suspension with a lot of triangulation, the axle will rotate through travel and if designed well, will keep pinion pointed at the tcase output through travel. This is better suited to a double Cardan shaft.

A parallel link suspension will have the pinion angle stay relatively constant and is better with a single joint shaft.

A leaf suspension with a traction bar will try to rotate the axle somewhat through travel, and is why you see most people turn the pinion up and run a double Cardan when adding a traction bar in the rear.

If your pinion is parallel to tcase output run a single joint.

If your pinion is pointed at tcase output run a double Cardan.

To my knowledge, a single joint shaft can handle more angle than a double Cardan, but a lot of that has to do with joint size.
 
There is a ton of tech in choosing the right driveshaft type. How much lift do you have? What are the current operating angles of your driveshaft? What are the max operating angles of your shaft? How much street time does the rig see? An unbalanced shaft running on the road will eat bearings and seals proportionate to how much you run on the road and the speeds driven.

When I flatbellied my truck, it pushed my ujoints to the max operating angle and the tcase output was no longer on the same plane as my pinion. I cut the perches off and rotated my pinion to point at the tcase -1* (under acceleration, the pinion tips up a little bit) and got a DC shaft built by Olivers. I had made a shaft to keep me moving and it ran pretty smooth up to about 60mph. I am 150% happy with my decision to get one built by a pro. Now my homemade shaft is a spare.
 
Some good info guys. Thanks. Preciate it. Looks like I will know best when i get the axle under the new frame and look how parallel its. Like Mac said, if im there i can go single, if not then i gotta cut the perches and rotate.

a_kelley makes a great point. I didnt think about the weakness of the shaft, tho i had planned on sleeving it. Perhaps aftermarket can be an option at some of the prices mentioned here, but i refuse to pay 400 for a driveshaft. lol.
 


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