CV Clocking (if axles easily slide left-right)

[Sodo]

This quote harvested from another recent thread: Excess Axle Play - '90 Westy

[RBEmerson]

Remember what happened to Martin Luther when he nailed his 95 Thesis to the church door. The life of an iconoclast is not an easy one. ;D
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[ALIKA T3]

Hi Tom!

Clocking is more spread out than you make it sound. It's to get the best articulation benefit of the whole assembly. You don't need it on stock applications, but when rebuilding, why not? I do it, it doesn't cost me anything.

The axle movement left to right depends also of your van ride height. Stock height allows axle movement left to right, it's the design plunge to accomodate travel suspension, and it is normal. The axle self centers thanks to the boots and physics, thanks to-I think- the ramps in the cv ball races, it's just gonna find its happy median place naturally.
The play to watch for is against the clock, and up and down from the flange into the differential, and also from the cv body itself. When you can feel these, it's beyond worn anyway, doesn't mean it's noisy yet though.

I've replaced my share of cv joints, a lot of them beyond worn, pitted to death, starting to be pitted within 20K miles from factory + 30 something years (which I attribute to the transmission ground strap now), loose cv's, original VW's cv's, replacement Löbros like OE VW (but without the VW logo), replacement GKN's ( recent ones with 3 lines, Löbro/GKN now), garbage brands too like Dansk (Roulex), Empi, Meyle, some 3 letter name shit I forgot too.
I've documented for myself a lot of models, different stars, cages, ball sizes even within the Löbro/GKN. Differences in early Vanagons using T2 211 part numbered CV's. Later T3 Vanagons with 251 part numbers.

I have driven 6 months as a daily with no cv boots as an experiment on old CV's with sticky Swepco 164 open gear grease. I have yet to see a loose axle hitting the flanges from a worn ass cv joint.
When that happens, it's most likely something is not right (anymore) in the equation from factory.
I listed on the forum here all the axle lengths and part numbers that ever existed for the Vanagon. Shit gets mixed up in 3 decades of poor maintenance, aftermarket crappy parts that fit 1979-1992 Vanagons ( ), suspension modified, engine swaps with angle change on the drivetrain, who knows. A worn CV joint alone doesn't send and leave the axle in the flanges in stock configuration while driving, that's BS in my opinion.
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Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[Sodo]

[ALIKA T3]

[Christopher Schimke]

[ALIKA T3]

I would say it's 360°/6 balls=60° by itself, and again maybe divided by 2 one more time for being at the exact possible opposite of the opposed CV's position (clocking).

So every 60° is the possibility of having one CV in the opposite behavior as the one of the other side of the shaft, when perfectly "unclocked". The splines on the shaft make variants of in-between "perfectly clocked" and "perfectly unclocked".

So now, what off the counter headache medicine do we ask for bc of Sodo's insomniac thoughts?
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget

[Wildthings]

I would suspect that clocking the CV's gives a quieter and longer lasting drive train. What it allow is for the outer races of the two joints to turn at exact same speed throughout the entire 360° of rotation. If you have ever driven a 4 wheel drive pickup with yoke style joints in the front end you have felt the effects of the two jokes of the joints not turning at the same speed throughout the rotation. CV joints are not actually constant as far as relative velocity between the outer race and the inner race, but the slight variation in velocity can be cancelled out entirely by clocking the two joints to each other.

[ALIKA T3]

[Sodo]

[Wildthings]

[Sodo]

Wildthings how do you know CVs are not constant?
Can you point me to this information on the web somewhere?

Proof of this is central to the discussion.
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'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered original gearbox
....KTMs, GasGas, SPOT mtb

[ALIKA T3]

[Wildthings]

[Christopher Schimke]

[Sodo]

[Wildthings]

[teej]

[RBEmerson]

Has the CV grease turned p*** yellow? ;D
_________________
Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[Christopher Schimke]

Okay, I was able to set this test up again to check my previous words about the binding. In doing so, I discovered that I was incorrect about the 90 degree rotation, but I also discovered something I did not realize last time.

First, I was incorrect about the binding being at 90 degrees. It was a long time ago that I did the last test, so my memory failed me. The binding is actually occurring every 120 degrees. Obviously, this makes more sense, given the number of bearings in the joint. Sorry for the incorrect information in the previous posts.

The test shown in the video below is with the axle set at a 20 degree angle to the joint. The noise in the video is the splines of the axle riding on the clamp, not the CV making noise.

With 944 CVs, and the axle at 20 degrees, the CV is in a pretty significant bind every 120 degrees. So much so, that it's a little hard to decipher what exactly is going on. As result, I switched the CV to one of our Hi-Angle CVs. The results were pretty dramatic.

With the Hi-Angle CV in place and the axle remaining at the exact same 20 degree angle, there is absolutely ZERO binding in the CV. And as a result of zero binding, I was able to observe the action that the inner star (and therefore, the axle) takes as the CV reaches the same location in the rotation that was causing binding in the 944 CV (every 120 degrees).

In the video below, watch the end of the axle shaft. See how it moves in and out (left - right)? This is showing how the inner star (and therefore, the axle) has a natural tendency to be pulled inward toward the CV body every 120 degrees of rotation. Obviously, as the inner star is pulled inward toward the CV body, the axle follows. (My hand on the axle is only putting light tension toward my right to ensure the axle is following the inner star perfectly, and to prevent the axle from "climbing" the clamp)

Keeping that in mind, think about what is happening to a CV mounted on the other end of the axle and installed on the flanges. If the CVs are NOT properly clocked (clocked 180 degrees from being in phase), both inner stars will be trying to move away from each other every 120 degrees of rotation. In essence, they are fighting each other trying to pull the axle, or themselves, apart.

However, when the CVs are properly clocked, they are actually complimenting each other during every rotation, like a dance. In other words, when one inner star wants to move inward toward the CV body, the opposite CV is loosening up and allowing that movement to happen.

Of course, there are the states in between fully tight and fully loose, but this seems to play very well into Tom's theory of the possibility of the axle making contact with the flange if the CVs are not clocked properly. It also makes one think about what is going on when the CVs are partially clocked too.

And then, of course, there are the states where the CVs are only partially clocked (partially out of phase) to consider.

VERY interesting.


Link


And for those who are interested, below are two photos showing the 944 CV in the portion of rotation that causes the binding to occur.

On the 20 degree side (first photo), you can see the narrow part of the inner star is located at the wide part of the CV body. On the opposite side (second photo), it's the wide part of the inner star and the narrow part of the CV body.

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