We had a most unusual break down on the run. The rear hub on a car broke apart. In this video, you can see the wheel fall off near the end...

Here's my own video of this section of the run. The wheel had already come off by the time I got there. My own car had a problem, too. The fan died, and it started boiling over when I stopped at the end of this video.

Looks like fun other than the breakdowns! I would love to drive my Fiero on those roads.

Here is a picture of the broken hub (and brake rotor) of the convertible (picture from carnut122)...

You can see the hub nut still on the axle. The mounting flange of the hub, and the "hat" of the rotor, are still attached to the wheel.

quote Originally posted by TopNotch: Here is a picture of the broken hub (and brake rotor) of the convertible (picture from carnut122)... You can see the hub nut still on the axle. The mounting flange of the hub, and the "hat" of the rotor, are still attached to the wheel.

Wow, what do we need to know about the rotor /hub, for example "bought at Autozone and made in China, or Mexico"?

[This message has been edited by 2.5 (edited 09-23-2014).]

We need to thoroughly inspect our cars prior to driving them like they are sports cars......

quote Originally posted by olejoedad: We need to thoroughly inspect our cars prior to driving them like they are sports cars......

As in, take the wheel of and look at the rotor for cracks?

I would love to see a closeup picture of the broken areas to study the failure mode.

I doubt the hub flange & the rotor hat failed at the exact same instant and pictures would help confirm this. I suspect the hub failed first and the hat kept the wheel in place until it failed as well. If they failed at different times, there should have been some strange noise/clicking, brake pad smell, etc coming from that rear of the vehicle before the wheel just came off.

Pictures sent to your e-mail, guru.

I must be getting senile. I've been thinking rotor, rotor, rotor and not hub. Of course the hub failed and then took the rotor with it. I actually have spare hubs for an 88. Maybe I need to put one in the spare parts kit for next year.

What are those wheels from? Was it still running the OEM bolt pattern? (wondering if a "not quite perfect" wheel fit might have contributed...)
Glad it wasn't any worse. That could have been real ugly had there been oncoming traffic.

The hub bearing failed allowing for a small amount of movement, the stress of swaying back and forth on the turns cracked the hub and rotor as the brake caliper held the rotor in place while braking, until both units failed due to metal fatigue caused by the constant flexing. We all know what happens when you bend a piece of metal over and over until it breaks. Note in the video the amount of flex in the body and suspension due to the top being cut off of the car. If you look at the picture you can see where the inside of the rim was coming in contact with the strut prior to the failure. The final break was caused when he got sideways and then locked up the breaks. This all could have ended far worse, especially with all the vehicles in such close proximity and once again that being a convertible driving on a mountain...

[This message has been edited by lou (edited 09-25-2014).]

From the pictures I received, it is clear the bearing hub failed first as it has signs of polishing where the two separated parts were moving relative to each other and grinding/polishing the fractured surface (looks like the entire surface was polished). I can't tell from the pictures if the actual bearing races were bad, but it is clear that the hub was separated for a while before the rotor hat gave way. The fractured surface of the rotor hat does not have any polishing and is cast iron, so once it let go, it was a total failure at that point. Its not surprising that it failed as it I also see signs where the strut was grinding the inside of the wheel.

The fractured hub and the back side of the wheel rubbing the strut should have been making some noise to give advance notice that something wasn't right. If the bearings were also bad, they should have been growling and it get louder when that side was loaded in a turn. Also with the rotor and caliper being the only thing keeping the wheel on, and the wheel tilting as it went through the many curves, it should have felt funny through the brake pedal (more travel to close the excess gap created due to the rotor not running true), not to mention the brake pads should have been getting hot and starting to smell.

Now, I am not trying to be critical here, just sharing that cars and mechanical things normally "speak" to us when things like this are about to happen. If we know what to listen for or can notice differences in the vehicles behavior, we should be able to stop and check things out before they become catastrophic.

I am just glad the situation didn't end up being any worse than it was. Would have been a good day to buy a lottery ticket for those involved.

[This message has been edited by fieroguru (edited 09-25-2014).]

quote Originally posted by fieroguru: ... The fractured hub and the back side of the wheel rubbing the strut should have been making some noise to give advance notice that something wasn't right. If the bearings were also bad, they should have been growling and it get louder when that side was loaded in a turn. Also with the rotor and caliper being the only thing keeping the wheel on, and the wheel tilting as it went through the many curves, it should have felt funny through the brake pedal (more travel to close the excess gap created due to the rotor not running true), not to mention the brake pads should have been getting hot and starting to smell. Now, I am not trying to be critical here, just sharing that cars and mechanical things normally "speak" to us when things like this are about to happen. If we know what to listen for or can notice differences in the vehicles behavior, we should be able to stop and check things out before they become catastrophic. I am just glad the situation didn't end up being any worse than it was. Would have been a good day to buy a lottery ticket for those involved.

I believe those wheels came off of a J-Body. Think Cavalier or Sunbird.
Although they do have more offset, I have seen them installed on LOTS of Fieros without issue. I'm wondering if the contact between the wheel and the strut happened after the hub broke, but before the rotor let go. At speed, it certainly wouldn't have taken long for the wheel to grind itself on the strut. It might have made a noise, but I'm thinking that, under the prevailing conditions ("brisk" speed, lots of tire squeal) it would have been more like " 'ziziziziziziziziziz' WTF? 'BANG!'"
I can't speak to the "polishing" of the hub, however. I wonder how long it took for that to happen.
Obviously, this is all speculation, since I wasn't there.

I posted on the FB thread that this is absolutely the first failure of this type that I have ever heard of.
I don't know if the same thing affects track-driven cars or not. I've heard of rear bearing failure, but I pictured exactly that - the bearings. Not the hub.
I hope this isn't the beginning of a trend. Seems like a lot of the high horsepower track-driven cars would be rougher on hubs than a Duke powered 84 on mountain roads.

[This message has been edited by Raydar (edited 09-25-2014).]