Assembling used CV joint with star “flipped” & line “inside”

[Sodo]

Has anyone ever tested this?
Ball-tracks are not dead-center in the CV, would this move the pressure-area to the fresh side?

With the access to (possible) new ball-tracks and all, it seems like a good thing to “know”
…..beyond the internet chatter.
Like really frickin’ “know”.
We know about reversing the axle direction (I think) but I don’t recall any pics of old+new ball-tracks from that method either.

First of all, before the “backwards assembly”….
Does anyone have or know of
—actual pics of a run-in CV where the axle direction was reversed (for its 2nd life)?

I can try this because CVs aren’t all that consequential.
Its not a huge investment to sacrifice a used CV to Vanagon Science.
But it’s gonna take a few years to get any data back (if ever).

Being a “guy”, I’m intrigued by this.
Ever since the realization that underwear has four fresh configurations (post-apocalytic environment, without laundry etc).

-------
ref: Bentley p42.9
_________________


'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop, EJ25, cooled filtered (original) gearbox
....KTMs, GasGas, SPOT mtb

All Vanagons should do this:
Add direct starter-to-chassis cable THEN delete ground strap at front transaxle mount.
The best time to do this mod was in 2010. The second best time is TODAY.
If your starter is slow, this is MORE important.

[dubbified]

I like the idea.. I do... but I've not tried it namely because bearings are easily replaceable. Maybe the idea to go cheap, should apply to beer, vs bearings.

Any bing search can find stories where seized axles outer or inner bearings destroy a transmission, or drive bearing. It does not sound like a safe thing to experience, or cheap. I could imagine that could have dire consequences to driving, control over the vehicle, you could lose control if at speed...........(insert sound of doom, and cash registers and screams)

When one of those fails, the force which can be exerted on the drive flange, and the drive bearings if one of those binds, or has major issues..

I do think of consequences I've heard of when those fail.. the pictures, and the $$ and effort to repair it, seems like a no brainer.

I'd replace them if they cant pass basic inspections, and have too much wear.

[Sodo]

[dubbified]

You are Lucky to have not had to deal with Axle (cv bearing) bind.

Here is a video of that occuring firsthand:

Link


The force is so great, it causes the motor to move. What forces would you think are at play, to cause that?

Example reference site, Search terms Cv or Constant velocity axle bind..
https://vehiclefreak.com/can-a-bad-cv-joint-affect...to%20fail.

and another,
https://carstopics.com/broken-cv-axle-could-mess-up-your-transmission/

I suppose bad alternators dont destroy batteries either.

I'm glad you've not had to deal with it, or repair the damage from a bad cv thrashing about. seized/Binding vs pivoting, which is what a cv bearing is supposed to do. I've even heard of axles straight up breaking.. in half.. where do you think the force comes from, and travels to/is transferred to, or what happens when that axle half broken shaft is affixed to the drive output cup, or what about the other half sticking out of the stub/axle on the suspension side?

I have had two axles fail/bind, one (Cabriolet MK1)put damage into the drive cup/bearing so the shop said.. and the other (GTI MK2)really worked the outer bearing. I rebuilt the trans, and rebuilt the bearings with new hubs. Both cars were 100K+ when I got them and needed love.

Now.. COULD prior damage from a PO been in the works for both cars.. maybe. The gear all looked pretty original to me.

[Sodo]

I’ve no doubt that a broken axle can cause a world of hurt and I’m sorry you (or your shop) had to deal with that. But Im focused on ball-track wear inside the CV, not busting axles and such mayhem.

I respectfully request that the discussion remains upon:
Assembling used CV joint with star “flipped” & line “inside”
….Or….
“moving the CV ball-tracks to a fresh surface”.

===========

Heres the CV. It a Syncro front Inner CV (same as 2wd). But the outer (steering) CV holds it “in place” axially so I think its a good CV to do this test upon.
Notice the “line” is outboard and the ball tracks (blue felt markers) are biased inboard. Sorry the blue marks are out of focus.

I assembled the CV with the star “inward” and the outer race “inward” and put a label on the CV shaft. But i also reversed the direction (moved R side axle to the L side). Violating the “one change at a time” rule of testing. Dangit.

Hopefully I’ll get some miles in and be able to look again some tens-of-thousands of miles later to see if the ball track has moved.
Or if any trouble becomes apparent.
& report back too👍🏽👍🏽👍🏽
_________________


'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop, EJ25, cooled filtered (original) gearbox
....KTMs, GasGas, SPOT mtb

All Vanagons should do this:
Add direct starter-to-chassis cable THEN delete ground strap at front transaxle mount.
The best time to do this mod was in 2010. The second best time is TODAY.
If your starter is slow, this is MORE important.

[dubbified]

Thanks!

Sure, but you're talking about re-orienting the housing in attempt to overcome wear inside the bearing, there is also wear upon the cross and cage to consider.

Goodluck! Be safe!

[djkeev]

[dubbified]

Thanks DJKeev,

Yea.. I do get the idea...

I'm glad to give my almost never used tube of prussian blue away for bench testing of the tolerances, but it may not work here..

[wesitarz]

No, being Sodo you are intrigued by this.

[Sodo]

Can’t help myself

When you get a CV apart “early” and there’s one small pit - it sure seems like there is space to find a 6 new wear areas ready for another 50/100,000 miles.
You can do that if you mark the axles etc and flip Left axle to right.

But what if we can get a 3rd use & 4th use?
Just by figuring out how to do it.

I’m not all that great with flipping & rotating. Then add disassembly and flip parts even further…….
It gets deep. But there are smart people here…
It would be cool if there was a simple instruction to flip your way further out of buying new CVs.
I know you can flip the drive & coast tracks, maybe that’s enough.
But this adds run#3 and run#4!

Here’s another thread where Waldo explains the “flippin’ thing”. CV joint pit too deep?
_________________


'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop, EJ25, cooled filtered (original) gearbox
....KTMs, GasGas, SPOT mtb

All Vanagons should do this:
Add direct starter-to-chassis cable THEN delete ground strap at front transaxle mount.
The best time to do this mod was in 2010. The second best time is TODAY.
If your starter is slow, this is MORE important.

[djkeev]

I'm willing to bet big money that there are many reused CV joints wandering our highways that have been innocently incorrectly assembled and have a boat load of miles on them!

Now...... to locate them......

Dave
_________________
Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[Abscate]

You can knock the high points of that pit, pack them with good moly grease, and run them another 50,000 miles, too.
_________________
🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🍊 🍊 🍊

[Wildthings]

There are CVs assembled wrong when they come out of the box and there were likely ones assembled wrong that were installed on the assembly line. Overall if you aren't running a steep drive shaft angle I don't think it is a big deal.

That said you can get very good life out of a CV joint by moving it from side to side and by flipping it end to end. Side to side changes the wear to the opposite side of the grooves and end to end will move the wear axially in the grooves. You can also move the wear axially by how you position the small end of boots on the axle.

My own experience is that the stingy amount of lube used on the factory CVs was a major problem and shortened the life of the original CVs considerably.

[fxr]

[Sodo]

Hmmmm. Some time to think about it.
I’m not good at digital logic, 2 bits & I’m maxed out.
But it helps HUGE to hear other descriptions.
Yesterday I couldn’t make anything of it, but today, reading some other descriptions of the variables, some clarity has returned.
I was able to reduce it to 2 bits.👍🏽👍🏽 (my logical limit!)

I think its NOT “fully” canceling.

The Syncro front axle is a little helpful in reducing the combinations, as it cannot be flipped end for end.
Inner CV remains inner.

There are only two variables resulting in 4 combinations.
Drive side/coast side
Line in/line out. (Keeping the star/outer as one unit)

Switching van sides flips the drive/coast.
I think “line in/line out” does cancel the drive/coast flip, but moves the ball-track axially.
Which was the main goal.
_________________


'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop, EJ25, cooled filtered (original) gearbox
....KTMs, GasGas, SPOT mtb

All Vanagons should do this:
Add direct starter-to-chassis cable THEN delete ground strap at front transaxle mount.
The best time to do this mod was in 2010. The second best time is TODAY.
If your starter is slow, this is MORE important.

[Abscate]

[Pchill2]

I can't provide any information specific to this application. I do have experience working in off road vehicle design, specifically power transmission and shafting.

I will say that flipping the axle in the rear of the vehicle Vanagon would have adverse affects but not likely on the CV joint. The shaft itself acts as a torsion spring on vehicles and over time will get work hardened and fatigue which results in inelastic deformation along the shaft axis. This can be observed by scribing a straight line along a new shaft and inspecting it after thousands of miles (especially off road). Not the best idea to completely flip the direction of torsion in that case.

I would just carefully inspect the heat treatment area around the drive and coast side of the ball track. If symmetrical, I would assume it would not be a problem to flip your joint.

Also don't forget to inspect your balls.
_________________
87 Syncro Westy
Honda K24 swap

[Sodo]

I think the 'knowledge' becomes useful

when you are servicing a CV axle,
and it has one or 2 pits,
and ya just wanna assemble it the best way

===================

[fxr]

[Sodo]