Alloy Wheel Failure

[Riccardo1973]

Last weekend one of the alloy wheels on my Volvo S60 cracked, fortunately this was at fairly low speed so I was able safely stop without causing further damage to the car.

I would be grateful for the views on what the likely cause of this failure would be. Manufacturing defect or just the poor quality of roads that we have to endure?

As you can see from the picture the wheel is now in two pieces with a crack around the whole circumference of the wheel. I didn't hit a pothole immediately beforehand, but there is some damage on the inside edge of the wheel from hitting a previous pothole.

[Flanders.]

Holy fk thats bad.

[GenePoolReject13]

WOW! Such a clean break!

[E30M3SE]

+1.

No expert, but I would have thought pothole would have cracked it across the width..........

[vrooom]

That sound like more your brake cailper sticking out..

[v8will]

Impact damage.

Impressive I must add.

[vrooom]

They dont have to stick out sideway, they could stick forward. maybe pad or cailper body.
A good rub from cailper down to 1mm or so on alloy around the rim can cause the wheel to spilt.

[The Wookie]

doogz said:

To my eyes, that's far to uniform and consistent all the way around to be anything other than a manufacturing defect.

Have to agree, a pothole or somesuch probably caused the failure but I've never seen one go like that before as they usually bend/kink. Either a batch made up with dodgy material or a failing in the design of the wheel.

If you cut the wheel in half I'd bet that would be the thinnest part of the wheel.

[The Wookie]

vrooom said:

That sound like more your brake cailper sticking out..

Looks too close to the inside face of the wheel to me to be interference.

It's also right at the highest bending load point if you strike something with the inner edge of the wheel

[Riccardo1973]

doogz said:

vrooom said:

That sound like more your brake cailper sticking out..

Radially?

I thought of that, but if it was sticking out, i'd expect the inside of the spokes to be marked. Even if it was the caliper/carrier, i'd still expect to see some other marking from it rubbing, that looks like a very clean break.

Take a look at the brake caliper and see what it looks like OP?

The brake caliper is not sticking out, or touching the wheel. The wheel shows no scoring or marks where the crack occurred.

I would have thought it was a manufacturing defect, but the wheel is 6 years old so imagine it would have failed before now if there was a defect.

[russell_ram]

The Wookie said:

doogz said:

To my eyes, that's far to uniform and consistent all the way around to be anything other than a manufacturing defect.

Have to agree, a pothole or somesuch probably caused the failure but I've never seen one go like that before as they usually bend/kink. Either a batch made up with dodgy material or a failing in the design of the wheel.

If you cut the wheel in half I'd bet that would be the thinnest part of the wheel.

I've had the EXACT same failure (Mondeo St Diesel). instantaneous fracture around the whole circumference of the wheel with (obviously) total deflation. Freezing cold day and pothole impact. Failure was at a machining feature on the inner face which you can clearly see in the second pic.

Sadly Ford weren't the least bit interested in even looking at it, car had only done about 1000 miles at the time.





Scarred the sh**t out of me when it happened BTW, fortunately I was only doing about 60mph at the time.

russ

Edited by russell_ram on Thursday 3rd March 11:14

[vrooom]

That's bad! that machined grooves, why it is there?

[russell_ram]

No not particularly, I did walk back to take a look and was surprised by how shallow it was - I did have a 'square' edge though. If the wheel hadn't fallen in half it would have stayed inflated. NO tyre damage (visually) not even a cut or mark on the sidewall. As I said, impact/fast fracture from a notch feature.

[lunaunderscores]

happened once or twice on vx220s too, was a recall - different kind of break tho

http://www.vx220.org/images/1/vx/vx220-alloy.jpg

[TheLurker]

lunaunderscores said:

happened once or twice on vx220s too, was a recall - different kind of break tho

http://www.vx220.org/images/1/vx/vx220-alloy.jpg

Now that would wake you up!

[Superhoop]

Has the wheel ever been refurbished?

[mikliska]

Looking at some modern aluminum wheel designs I've often thought they were too thin in some areas as a result of weight reduction while on the drawing board (screen). I'm not confident that all wheel designs are produced by people with knowledge of metallurgy.

[FranKinFezza]

Stress failure from a prior impact.
They can take quite some time to show up depending on loading forces and time.
And usually as the pictures show they fail at the point of maximum force/loading
acting on the alloy.