Failed CV joint shaft... cause/opinions?

[MWP]

Hi all,

So this happened yesterday on my ST185 GT4...
The front left end of the CV joint has sheared off.



Now im trying to work out what has caused this...

Ive had a bearing noise for sometime.
I checked the wheel bearing a few weeks ago, but there was no play in it and felt smooth(ish).
Both the CV joints (inner and outer) are new, and also feel ok.
I did notice however, that the output shaft from the gearbox has some play in it, so figured it was that causing the noise.
Now that i do have the hub off the car, the wheel bearing is due for replacement (feels notchy), but doesnt seem bad enough to cause this kind of failure.

So my questions to you guys....

Is having some play on the output shaft of this gearbox normal?
There is around 2-3mm of in/out play, and 1-2mm of sideways/rocking play.

If its not normal, would that have caused this failure?
If not, what would?

Thanks in advance!!

[MWP]

Some better photos...

[Tweak]

Either it was loose or it has been done up too tight
Also were is the washer that sits under the nut, cos to me it does not look like one has been used going by the wear marks on the hub center

[KENut]

Thats weird. Looks like it failed because it was too tight.

The spline wasnt loose at all?

[allencr]

If not, what would?

Impact wrench/rattle gun or a 2m pipe.

[takai]

220Nm according to the Toyota manual.

I would say though that the lack of the washer certainly helped with localising the stress riser at the top of the stub axle where the thread was winding past.

With those highres photos ill retract what i said on the phone, thats just done up to tight.

[MWP]

There was a washer, it's just not in the photos.
It's the washer that came with the CV.

I did it up with the torque wrench to 200, the limits of the wrench.
Then I put a breaker bar on it and did it up a bit more, until the castlated nut lined up to get the split pin through.
Tight, but not overly tight I didn't think.

[thechuckster]

send hi-res pics of the crank to Old Corollas? He knows about crack-propigation stuff? Are the dirty spots on the crack face from you pulling things apart or were they present when i all went clunk?

inner seal face on the CV shaft looks like it was leaking/failing?

as soon as it cracked off, you would have had strange loads on the bearing faces as the only thing holding it all together was the brake caliper/disk/pads

fwiw: i thought that nut was tightened to something around 160 ft/lb (is that ~200Nm?)

[MWP]

As Takai said, BGB says 220Nm....
The cracked surfaces have been kept clean.

Maybe the aftermarket (non-genuine) CV had a fault.

[wa5]

Aftermarket? as in Chinese?

say no more.

[Xauterus]

If you look at the rust on the face that presses against the bearing, there is a lot of rusty powder there. It suggests that the nut holding the assembly together was not tight and the rust was from the surfaces fretting against each other due to that. That would caused flexing in on the splined shaft and loads on the threads.

[wht185]

I've had this happen twice to me once on my GT4 and once on an st162 what i found is that a seized brake will cause shear force on the cv at that point when the car is accelerating causing it to snap after repeated use so check the brake caliper before repairing the hub/cv

[MWP]

Seized brake?
How does a brake seize?

[wht185]

The Caliper slide pins are the usual culprit check to make sure they slide freely that's what happened to me the first time the second time I installed the handbrake incorrectly which caused it to rub also the pistons in the Caliper can seize so try pushing the piston in to check it moved properly.

[MWP]

Oh right.
Interesting....