47 replies to this topic

[FTodaro]

This past weekend I had a rear hub failure.It cracked all the way around the axle and then split. I did not notice it when i was in the race but after i could hear rubbing.

 

Anyone see a failure like this. I was lucky it did not separate.

 

 IMG_05441.jpg   14.21KB   133 downloads

[38bfast]

This past weekend I had a rear hub failure.It cracked all the way around the axle and then split. I did not notice it when i was in the race but after i could hear rubbing.
 
Anyone see a failure like this. I was lucky it did not separate.
 

IMG_05441.jpg

I have never seen one do that but was always afraid it could happen. We always replace the hub if a car takes a hard hit in the rear wheel. You are lucky the wheel did not just fall off. Of course if it did fall off it would be when you were right next to a wall. Not good stuff.

Glad to see you only have to fix one part and not the whole side of your car.

[Keith Andrews]

Wow, that's ugly.  You need to stay off the curbs Frank    I think about all stress the car takes when I hit those gators before the bridge (track left) going up the hill at Road Atlanta.  Which hub was it?

 

The good news is, you won't have to take the bearing off the hub when you replace it.

[Bench Racer]

This came from the production car site, 3rd post.

http://prodracing.co...php?f=7&t=14557

[FTodaro]

Wow, that's ugly.  You need to stay off the curbs Frank    I think about all stress the car takes when I hit those gators before the bridge (track left) going up the hill at Road Atlanta.  Which hub was it?
 
The good news is, you won't have to take the bearing off the hub when you replace it.

It was the left rear, I just replaced the bearing last season.

The stress must build up over time as I really did not hit anything this past weekend at Mid O.

A big thank you to Dan Thiel from Berg racing, Websrter NY, who just so happened to have a spare knuckle and half shaft assembly I could borrow to finish the weekend.

[Rob Burgoon]

I've had something similar to that.  Didn't fall off either.

[Jim Drago]

Flyin MIATA is making a stronger replacement hub. It is not legal. Perhaps something we look at if this problem continues. I have not had it happen to me personally, but have heard of these failures

[Bench Racer]

Perhaps if a major contributor to hub failure is the current Hoosier tire we need go to a tire with less grip.
Never viewed or read about rear hub failures untill the Hoosier tire.   Bearings, yes, hub failure, no.
Also never heard about Torsens taking a crap untill the Hoosiers.
 
Maybe we need to go back to a less grippy tire to be cost effective for the class.

[chris haldeman]

I had it happen too 2 of my customers. One was noticed on pit out by another competitor who noticed the wheel not running true and stopped the guy before he went out. The other launched the wheel during a race at Hallet in June this year. This car was prepped for the NASA champs a few weeks ago so I installed new built hubs on both sides. After looking at the rear hub that didn't fall off at Hallet I found it too be cracked all the way around I have no idea what was holding it together.

[FTodaro]

This could have been ugly, I guess, another item on the check list when swapping tires us to take a quick look at rhe hubs. Had no idea this could happen.

[Killian]

Perhaps if a major contributor to hub failure is the current Hoosier tire we need go to a tire with less grip.
Never viewed or read about rear hub failures untill the Hoosier tire.   Bearings, yes, hub failure, no.
Also never heard about Torsens taking a crap untill the Hoosiers.
 
Maybe we need to go back to a less grippy tire to be cost effective for the class.

 

This came from the production car site, 3rd post.

http://prodracing.co...php?f=7&t=14557

That SM6 looks like it was mounted on a 15x9 6UL with XIDA coilovers, so the car has a lot of grip.

[FTodaro]

I will throw this out not sure it's relevant, I had to use heat on one of the hubs to get it off, I just can't recall if it was the one that failed. I wonder if heating the would cause stress fractures, "Bennett" what is your thought?.

[Caveman-kwebb99]

Frank I am no metalurgist...  But keeping the car on the pavement might help  

[Keith Novak]

I will throw this out not sure it's relevant, I had to use heat on one of the hubs to get it off, I just can't recall if it was the one that failed. I wonder if heating the would cause stress fractures, "Bennett" what is your thought?.

Unlikely.  Think about how hot your brake rotors get.  They're transferring plenty of heat to the hubs so you've been heat cycling the hubs over and over.  One time with a torch isn't going to change that much.

[Todd Lamb]

Don't pick on Frank just because he forgets the e-brake is on every now and then.

[htron435]

Friggin' Hoosiers.

[Muda]

Yes, enough heat will make the metal brittle.  A friend bought a car a few years ago where the last owner had welded the back of the wheel studs to the hub, probably because the splines were chewed up so badly that they would spin.  After a very light RR wheel rub I handed the car off to my co-driver.  After a couple of laps the wheel almost fell off.  Studs broke at the welds and the holes for them were broken off in the area of the welds only.  Could have ended badly.  Enough heat will do the trick.

[Todd Tagget]

Frank I am no metalurgist...  But keeping the car on the pavement might help

drink through my nose on keyboard..

[Juan Pineda]

We've seen the hubs break circumferentially so the wheel falls off completely.

[Keith Novak]

Yes, enough heat will make the metal brittle.  A friend bought a car a few years ago where the last owner had welded the back of the wheel studs to the hub, probably because the splines were chewed up so badly that they would spin.  After a very light RR wheel rub I handed the car off to my co-driver.  After a couple of laps the wheel almost fell off.  Studs broke at the welds and the holes for them were broken off in the area of the welds only.  Could have ended badly.  Enough heat will do the trick.

THAT much heat will do the trick.  Welding a loose stud sounds like an absolute recipie for fallure, but a completely different type of failure than Frank's hub.