Minimum CV angle

[turboshad]

I can find stuff of the max angle of the inner and outer CV joint but I can't find anything on a recommended minimum angle. From what I can find it isn't desirable to run them at 0° but I can't find what a minimum angle might be. Any thoughts? As long as it isn't zero are things OK? Thx.

[BadAssPerformance]

I can find stuff of the max angle of the inner and outer CV joint but I can't find anything on a recommended minimum angle. From what I can find it isn't desirable to run them at 0° but I can't find what a minimum angle might be. Any thoughts? As long as it isn't zero are things OK? Thx.

It depends on how much the suspension articulates. No matter what angle it is at, if it stays at that point the grease will get fret out of the way... Even 0° ay "curb" is OK with enough movement to spread the grease around.

[turboshad]

Any idea from a strength perspective? Should I max out the angle at full droop and have it coming closer to zero but not really caring at ride height or try to find a combo that gives me the most angle at ride hight while not exceeding the max at full bounce or jounce? My gut/intuition says you would get the most strength at 0° but that doesn't come from any experience.

[A.J.]

I had more angle than most when I lifted my van. My van weights 3800 lbs and ran 14.7 in the 1/4 mile with no issues. It is currently back to stock ride height in the front.

With the suspension hanging down, you want to make sure the inner joint won't pull apart. You can push on the boot and to see where the inner bearing sits in the cup. If it's even with the inner cup you're getting close to the end of it's travel without it pulling apart.

[turboshad]

Ya, I should be able to control axial travel. I'm getting pretty close to either custom axle lengths and or making some billet uprights. If I take the plunge I've been wavering on custom uprights will be in order anyway.

[Reaper1]

I'll do some looking of my own, but where does it say to NOT run them at 0*? That makes no sense to me, honestly.

[turboshad]

I haven't read any real document that says it's not OK to run them at 0° but I've read it's bad for them to stay in one spot for too long or they can create hard spots. I suppose with the suspension travel that won't be a real issue but the one part that makes a bit of sense is that the axial displacement for a given CV angle change will be greater if the original angle is greater. For example for a 10° change the axial displacement is almost 3X greater if that change is from 10°-20° than if it is from 0°-10°. I could see that the greater the displacement the better as it won't heat or wear the same area as much but in my application and for how much I drive the car I'm not sure it will really matter.

[Reaper1]

I agree that it makes sense for the axial displacement to be greater at larger angles. I also agree that suspension travel will probably be enough to keep the grease happy. Keep in mind also that the grease is going to get warm and it will tend to flow easier in that state.

[shackwrrr]

Lots of OEMs using CV driveshafts in the front with independent front suspension. They run at practically 0* and the angle never changes. I don't see very many problems with them unless the boot gets torn.

[shadow88]

Lots of OEMs using CV driveshafts in the front with independent front suspension. They run at practically 0* and the angle never changes. I don't see very many problems with them unless the boot gets torn.

You must mean solid axle truck/suvs, like the grand cherokee?

[5DIGITS]

There are two reasons that a minimum angle should be used.
The first is the ball and needle bearing movement to avoid localized wear and extend CV joint life.
The second is grease displacement to insure the components circulate lubrication.
A minimum 1-1.5 degree angle is desired for distributed wear and lubrication, while suspension travel is secondary extended movement.

[shackwrrr]

You must mean solid axle truck/suvs, like the grand cherokee?

independent front suspension with the differential mounted to the frame and stationary, the driveshaft on those is cv lots of times and never moves (other than body flex)

[BadAssPerformance]

There are two reasons that a minimum angle should be used.
The first is the ball and needle bearing movement to avoid localized wear and extend CV joint life.
The second is grease displacement to insure the components circulate lubrication.
A minimum 1-1.5 degree angle is desired for distributed wear and lubrication, while suspension travel is secondary extended movement.

[turboshad]

Excellent. Thanks guys.

[Reaper1]

Answers my questions and verifies that the way I was going to set mine up will be fine.

[bakes]

There are two reasons that a minimum angle should be used.
The first is the ball and needle bearing movement to avoid localized wear and extend CV joint life.
The second is grease displacement to insure the components circulate lubrication.
A minimum 1-1.5 degree angle is desired for distributed wear and lubrication, while suspension travel is secondary extended movement.

ok i under stand what your saying and agree with it . But lets look at the Drag racing side of it for a sec. (non daily driver) Which angle is going to help c/v and splines last longer at hi power use?

[zin]

A straight line would be most efficient, and that should mean lower loads on the components... but I'm looking to 5digits for validation.

Mike

PS My comments are in regards to a drag only situation, I would expect wear issues in a street /strip application.

[5DIGITS]

ok i under stand what your saying and agree with it . But lets look at the Drag racing side of it for a sec. (non daily driver) Which angle is going to help c/v and splines last longer at hi power use?

Looking purely at the performance perspective, the minor angle will have near immeasurable torque/power loss, when compared to a zero angle installation.
Not until much higher angles are used will the losses increase and at that point the stresses on the shaft/joint will also increase because the losses are being absorbed/consumed within the shaft wind-up and joint angle.
Therefore, the difference between a 1-2 degrees and zero degree angle are common between an on-road and drag strip application.

The missing element(s) in this topic when discussing a 'drag strip' only application is the chassis transfer amount and plunge depth.
The vehicle launch is the highest demanding moment for the shafts due to initial vehicle mass loading, gear ratio torque multiplication, and drive-line shock.
In this case, the weight transfer height should be measured or estimated to know what the shaft angle is, under that condition.
The next step is to raise the front of the car to the 'launch angle' (preferably with the rear height also duplicated) and then adjust the driveline angles within the 1-1.5 degree position.
This will produce the optimal condition for shaft/CV durability, torque transfer, at the highest stress level in a drag race application.
When the engine angle and installation height have been manipulated the plunge depth can now be determined.
The plunge depth is the distance the tri-pod extends into the CV housing and on non-lowered vehicles is significant contributor to CV assembly failure.
The shallower the plunge depth (outward from the differential) the greater the chance of shaft failure because the loading is extended away from the CV yoke and higher torsionals are realized.

In short for drag strip applications, the angle must be maintained as described above but just as important the plunge depth needs to be kept as tight as possible without bottoming out the CV, under other driving conditions.
When these two main items are addressed, the CV durability will be at its peak potential for a drag race only application.

[turboshad]

Ya, that's sort of where my head was going though not in quite as much detail. Didn't think about setting the angle at "launch height" though. Great tip, thanks 5D!

This question came about from some extensive remodelling I'll be doing with the front end and where the best engine placement might be so this helps allot.

[Reaper1]

Looking purely at the performance perspective, the minor angle will have near immeasurable torque/power loss, when compared to a zero angle installation.
Not until much higher angles are used will the losses increase and at that point the stresses on the shaft/joint will also increase because the losses are being absorbed/consumed within the shaft wind-up and joint angle.
Therefore, the difference between a 1-2 degrees and zero degree angle are common between an on-road and drag strip application.

The missing element(s) in this topic when discussing a 'drag strip' only application is the chassis transfer amount and plunge depth.
The vehicle launch is the highest demanding moment for the shafts due to initial vehicle mass loading, gear ratio torque multiplication, and drive-line shock.
In this case, the weight transfer height should be measured or estimated to know what the shaft angle is, under that condition.
The next step is to raise the front of the car to the 'launch angle' (preferably with the rear height also duplicated) and then adjust the driveline angles within the 1-1.5 degree position.
This will produce the optimal condition for shaft/CV durability, torque transfer, at the highest stress level in a drag race application.
When the engine angle and installation height have been manipulated the plunge depth can now be determined.
The plunge depth is the distance the tri-pod extends into the CV housing and on non-lowered vehicles is significant contributor to CV assembly failure.
The shallower the plunge depth (outward from the differential) the greater the chance of shaft failure because the loading is extended away from the CV yoke and higher torsionals are realized.

In short for drag strip applications, the angle must be maintained as described above but just as important the plunge depth needs to be kept as tight as possible without bottoming out the CV, under other driving conditions.
When these two main items are addressed, the CV durability will be at its peak potential for a drag race only application.

Well said. Verifies exactly what I was going to do.