CV vs. U-Joint

Co-Dog

Well-Known Member
Has anybody ever tried using CV joints instead of u-joints on a driveshaft? I assume there must be a very good reason that I haven't seen it.
 

partybarge_pilot

Well-Known Member
Yes, I prepped a MTG stadium truck that had one in the front. Using a cardian joint would accomplish the same thing for a lot less money.
 

manualshifter

Well-Known Member
AW: Re: CV vs. U-Joint

Based on what I´ve seen so far:
CV´s create more heat, have the risk of getting the boot damaged and are more sensitive to a good service. But if you have a good one, you reduce vibrations, which can help other components of the driveline and the car.
U-joints are usually much cheaper and less risky.
 

jpndave

Well-Known Member
I am no expert on the subject but what I have found out in my experiences and research is that the CV joints don't handle the higher speed a driveshaft has. Boots end up a real problem at higher speeds (can't use slow speed high angle boots). On the halfshafts, they are running at 1/4-1/5 (depending on your diff ratio) the speed of the driveshafts. Torque loads are less but at the higher speeds, they want to throw the balls out of the joints. The GKN catalog has formulas for all of this but finding real world numbers to plug in ends up a bit of a guess I think and Honestly, I would trust those here with experience more than the numbers (like partybarge_pilot). I have an issue on my current project that would really be easier (and probably smoother) to do with a CV but I am nervous to do it and will probably end up using two double cardan joints on the front and a u-joint/double cardan rear. There is some really good info here: http://www.4xshaft.com/index.html
 

partybarge_pilot

Well-Known Member
I have an issue on my current project that would really be easier (and probably smoother) to do with a CV but I am nervous to do it and will probably end up using two double cardan joints on the front and a u-joint/double cardan rear.
Why 2?
 

Jess@HighAngle

Well-Known Member
c/v's belong on a 1/2 shaft in many cases - due to speed and rotation and heat - U joints on Driveline's -That's my take -the c/v's don't like the speed and the boots just suck! Jess
 

Co-Dog

Well-Known Member
Thanks for the input, guys. After we went to link suspension and tore a C4 in half, I got to wondering if CV joints might be a viable solution. Since then, I read somewhere that Audi has been working on putting CV driveshafts into an all wheel drive production car. Maybe it will be possible some day, at least on the street. The boot will probably remain an Achilles heel for off road use. 2 shafts and a center bearing seem to be working just fine.
 

jpndave

Well-Known Member
The angle on the lower u-joint would be too high due to the compound angle made by centering the differential in the chassis. In a double cardan setup, the cv is at an angle and the regular u-joint is kept near 0 by tipping the differential to point at the double cardan. The double cardan would run fine but the u-joint would create all kinds of vibration with nothing to cancel it out, hence the need to run 2.
 

powerbox_builder

Well-Known Member
Since then, I read somewhere that Audi has been working on putting CV drive shafts into an all wheel drive production car. Maybe it will be possible some day, at least on the street.
Audi, Volvo, and BMW have been doing it for years, they call it a propeller shaft, but they have very little angle, and the boots are always where the failures begin.
 

Co-Dog

Well-Known Member
Audi, Volvo, and BMW have been doing it for years, they call it a propeller shaft, but they have very little angle, and the boots are always where the failures begin.
LOL---I'm sure I read it online, but never bothered to look at the date.:D
 
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