The broken aftermarket CV-axle issue

[Ed Lijewski]

I read that thread when you first posted it, and in my reaction to it above I screenshot the last post which has this:

"Let me put it this way, on may Baja I have ran without the concave washer for over 7 years, and I have pounded the snot out of it. With stock suspension you will NEVER pull off the circlip. There is no force applied to it on a normal street bug. However, if you increase the rear travel, but use stock axles, there will be a point where the CV does excerpt force on the circlip. However, in 99% of the cases, the circlip stays in place and the CV joint inner cage breaks."

Each of my failures have the circlip remaining in place and, it appears, the CV joint inner cage has broken. So as my Scorpios in no way increased their rear travel, our assumption must be that the axles provided are incorrectly dimensioned. And the spring collar plays no role in those failures.



YMMV

[brokencase]

When the axle let go at Carlisle...

Did you hear any thumping from the CV before it broke? (hours before or moments before?)

Were you accelerating?

Did you hit a bump?

[my8950]

When the axle let go at Carlisle...

Did you hear any thumping from the CV before it broke? (hours before or moments before?)

Were you accelerating?

Did you hit a bump?

Since he was the only one there at the hotel, I suspect he was practicing holeshots in the back lot...

[brokencase]

A few more ideas...

The only thing limiting the full extension of the rear suspension on the Scorpio is the shocks. What shocks do you have installed?
Are they the proper type or have you substituted something like Explorer shocks? Failure scenario here would be at some earlier point you went over some rolly polly hill (or bump) and the rear suspension extends more than it should and it cracks one of the CV cages but it still is intact. Later on you apply torque accelerating away from the hotel and then it lets go.

Also - You really should check the the rubber mounts on the differential (of your Scorpio and your XR)

[Ed Lijewski]

Since he was the only one there at the hotel, I suspect he was practicing holeshots in the back lot...

Sorta; there is enough room there to warm up the slicks.

https://m.facebook.com/story.php?story_ ... 3490100835

YMMV

[Ed Lijewski]

When the axle let go at Carlisle...

Did you hear any thumping from the CV before it broke? (hours before or moments before?)

Were you accelerating?

Did you hit a bump?

No warning of any kind.

Was gliding along at ~35 mph. Had exited from a gas station a mile earlier via a normal ramp.

Was on the main road towards the hotel. Roadway in good condition.

YMMV

[Ed Lijewski]

A few more ideas...

The only thing limiting the full extension of the rear suspension on the Scorpio is the shocks. What shocks do you have installed?
Are they the proper type or have you substituted something like Explorer shocks? Failure scenario here would be at some earlier point you went over some rolly polly hill (or bump) and the rear suspension extends more than it should and it cracks one of the CV cages but it still is intact. Later on you apply torque accelerating away from the hotel and then it lets go.

Also - You really should check the the rubber mounts on the differential (of your Scorpio and your XR)

Monroe I believe (white tube). Look to be okay. Not old/dirty nor sign of leakage. P.O. was a woman and car came with loads of receipts, so assumption is they are correct PNs. I have a stash of new shocks and struts but there's no indication these are used up and need replacing.

My other three rides have had new diff mounts installed. The diff mount on this car passes the index finger tip test: it's not sagged if you can insert your finger tip between the rubber bushing and the metal mount.

YMMV

[Ed Lijewski]

As I have a sense that some (you know who you are ) haven't read or resist considering John Brennan's CV failures alongside mine (or vice versa..), here's his opening post:

"BANG! A Tale of Two Broken Halfshafts

Post Wed Sep 19, 2012 12:36 am

I tell 'ya folks, I'm right on the edge-- RIGHT ON THE EDGE!

A couple of weeks ago, my right halfshaft, having had some excess play since I acquired the car a little over two years ago, was finally starting to give me some serious indication that it was time for replacement.

I acquired a remanned unit from Auto Zoo, and set about the painful process of removing the old Torx bolts... bought new hex-head bolts to prevent the silliness in the future.

Finally got the replacement unit in the car, and drove down a short dirt road to a main road, turned onto it, and gave it a little gas. Shifting into second, I gave it a little more gas, and...
BANG!

No power to the wheels! After being towed back to Tom Dooley's shop, I could see that the axle was broken, the outer boot wrinkled up, lots of play in the joint. It seemed like the cage had broken.

I'll skip the part about trying to obtain a new part from the same source, and having that part be the wrong part, then having to order another reman, since as it turns out, the new part wasn't really available...

Finally got another remanned unit, lubed it up, and installed it. I drove down the dirt road to the main road, turned onto it, and gave it a little gas. Shifting into second, I gave it a little more gas, and...

BANG!

SAME EXACT RESULT...

I'm at a total loss here. What in the hell could I be doing wrong? Or could two parts fail in exactly the same way, under exactly the same circumstances?"

Yes, John, it seems likely now that even more than two same parts can do that (Scout's Honor).

YMMV

[brokencase]

The only way I can see the cages breaking is if the CV was pushed beyond it's angular limits.

Torque is well managed by the balls and races...which are very "beefy"

There is always the option for those heavy duty CV's I mentioned earlier. They have chromoly cages.

You could probably install them with the stock 6mm bolts if you install 1mm wall tubular spacers around each bolt.
Otherwise you have to drill out and tap the flange holes out to 8mm.

Alternatively you could try installing these chromoly cages into standard CVs.
https://www.ebay.com/itm/112790102207

[Ed Lijewski]

I eagerly await axle shaft length, and Overall Collapsed Length of entire CV axle unit, of the failed unit and an OEM Merkur unit from Noah.

YMMV

[Ed Lijewski]

Posted by the guy doing that bad-ass turnout in the video I linked to above:

viewtopic.php?f=30&t=39579

YMMV

[my8950]

Posted by the guy doing that bad-ass turnout in the video I linked to above:

viewtopic.php?f=30&t=39579

YMMV

Ridiculous....

[my8950]

Ends are cleaned, nothing with them I can think of that would cause this failure.
This is one side below.

[my8950]

The other end on this axle had some strange wear marks and peeling.
I don't believe this would cause the failure, but still strange to see for as few miles as these have, less than 5k?
Ed will know for sure. I've got axles with 100k on them, haven't seen this type of wear on the ends.
Chinesium?

[my8950]

Two more photos on the sketchy end of the axle.