Wheel axle snapped whilst driving home from the garage it was 'repaired' by!

Barnabyhb

Yes the stub axle has snapped. you can see the other half of the stub axle in the wheel still in place within the wheel. Can't upload pic or url as new user. Its the axle/spindle in the centre of the disk/drum. basically houses the entire wheel and all its components.

EdGasket

AdrianC wrote: »

The stub axle won't shear if the bearing fails. The bearing might collapse, leaving the wheel to flollop about, or even fall off. The bearing might seize, locking the wheel... But the stub axle SHEAR? No.

The most likely cause I can think of for a stub axle shearing is impact damage. But the most likely result of impact damage, apart from damaging the wheel and tyre, would be to cause premature failure of the bearing...

WRONG The heat from a worn or faulty bearing causes the stub axle to shear completely off losing a wheel. Known it happen.

Most likely it is a taper bearing and the mechanic overtorqued it to some silly ft-lbs that are meant for the fronts. Taper bearings only need 25 to 30 ft-lb or just enough to stop the wheel wobbling.

Astronaughtwannabe

+1

I've known it happen as above.

AdrianC

EdGasket wrote: »

WRONG The heat from a worn or faulty bearing causes the stub axle to shear completely off losing a wheel. Known it happen.

After five minutes driving?

Still, if that has happened, there'll be some serious blueing and other sign of massive over-heating (rather than just being hot to the touch, which is not exactly abnormal).

Barnabyhb

EdGasket wrote: »

WRONG The heat from a worn or faulty bearing causes the stub axle to shear completely off losing a wheel. Known it happen.

Most likely it is a taper bearing and the mechanic overtorqued it to some silly ft-lbs that are meant for the fronts. Taper bearings only need 25 to 30 ft-lb or just enough to stop the wheel wobbling.

That's exactly what I was thinking. Is it possible to tighten it so much to cause the bearing to fail yet the wheel still be able to spin?
Or would the whole wheel just skid? as the wheel was rolling right until it snapped.
thanks.

AdrianC

Barnabyhb wrote: »

Is it possible to tighten it so much to cause the bearing to fail yet the wheel still be able to spin?

If you massively overtightened the bearing, so much that it wouldn't rotate, then the bearing could, theoretically, spin in the housing or on the stub axle - but you'd certainly notice to drive the car.

And, even then, I doubt the first failure would be the axle shearing.

It should be straightforward to tell if the bearing's failed, though - does the sheared-off bit of stub axle rotate freely in the brake? Are there signs of heat blueing on the stub axle?

How hot was it? Hot to the touch, or REALLY, REALLY hot - several hundred degrees centigrade?

misimp

I had a stub axle sheer whilst taking a corner in town on a newish car


It was put down to a flaw in the metal

EdGasket

Barnabyhb wrote: »

Is it possible to tighten it so much to cause the bearing to fail yet the wheel still be able to spin?
thanks.

Yes; that's why it is important to torque up the bearings correctly. A front-wheel drive wheel bearing could typically have 5 X the torque of a rear-wheel taper bearing. You can also tighten up a taper bearing by 'feel'; just enough to eliminate wobble at the wheel rim but no more. Often an overtightened bearing will fail quite quickly and howl like an engine, it can also overheat sieze and rotate in the hub or on the shaft and in the latter case cause the shaft to break.

Check the axle remains for signs of overheating; blueing as per previous poster.

colino

If there was a catastrophic failure after 5 minutes of driving, it wasn't the wheel bearing. If a bearing was torqued down too far it would lock, just as if that sides hand-brake was jammed on and you would have heard the squeal from the tyre dragging going 5 feet, not 5 minutes.
Get it back to the repairer for a check, they'll look for bluing and other potential faults and they might fix it themselves or come up with another possibility: Sudden Wheel-Kerb interface for example.

esmerobbo

What car was it? Some bearings need pulling off and pressing on, if you aint got the right tools some use a big hammer.

Big hammers can cause fractures!