Driveshaft phasing with CV joints

[Julian West]

Dear All,

When assembling CV joints on half shafts, should we be mindful of phasing?

Does phasing only occur when using U-joints?

Am I right in thinking the Constant Velocity joint eliminates phasing, regardless of its orientation?

Thanks in advance for any input.

Kind regards
Julian

 

[Jac Mac]

Dear All,

When assembling CV joints on half shafts, should we be mindful of phasing?

Does phasing only occur when using U-joints?

Am I right in thinking the Constant Velocity joint eliminates phasing, regardless of its orientation?

Thanks in advance for any input.

Kind regards
Julian

When you have one U-Joint & one CV the rotational speed change occurs either side of the U-joint and increases with the angle of that joint. Since the CV is just that it will transfer the rotational speed difference either thru the tire or into the transaxle gears depending where the U-joint is located . If its thru the tire the sidewall will try to absorb it, low profiles will make it worse. If its thru the trans then donuts or some form of elastomer etc will help. So the CV wont help with reducing the effect of phaseing other than placing the CV at the greatest point of half shaft angle change which will depend on some other factors like trans height in relation to axle hub.

 

[Julian West]

Thanks Jac,

I appreciate your clear explanation. I apologise, I didn't word my post very well. I should have made it clear that the half shaft has CV joints at both ends.

Do the two CV joints either end of the half shaft need to be aligned with each other to avoid phasing? Or am I right in thinking that a CV will not create phasing?

 

[Brian]

I think the CV (constant velocity) aspect of a CV joint makes it unnecessary.

Mixing a CV and a U joint on a half shaft sounds like a certain receipt for disaster at high speeds. With 2 U joints, equal angles and proper phasing, you can almost eliminate the inconsistent rotational velocities between the wheel and transaxle, and the shaft's vibration is isolated to the shaft, but with one CV and one U, your transaxle in the middle is getting a beating.

 

[Julian West]

Thanks Brian,

I appreciate your input.

To clarify, I am not mixing UJ's with CV joints. Apologies for any confusion caused.

 

[DaveC]

Contact Mike at MyRaceShop, he builds and races, our CV go-to guy.
https://www.myraceshop.com/930_CVs.html