Thread: Failed front wheel bearings - where did I go wrong?

Originally Posted by ballbag

Removed bearing yesterday and compared to new cheapo sourced from UK (box branded ‘Vorderkante’).

Noticed old bearing had no o-ring or gasket sealing ABS sensor. New bearing has an o-ring for the probe and 2 metal gaskets for the mount.

Also jogged my memory of the first replacement not having a rubber seal for the assembly itself to seal against the knuckle. That bearing went back to supplier and warranty was honoured and they either didn’t notice or didn’t care.

Waiting on some new brake rotors to arrive before torquing up new axle nut.

Hopefully this one makes it through winter.....

Front hubs do not have an O ring seal they have a seal inside on the axle into the tube, Rear hubs have an O ring
The O ring for the sensor is part of the sensor kit and comes with a sensor, the reason you wouldn't find one on a bare hub assembly, but your replacement one obviously included one .

Originally Posted by Roverlord off road spares

Front hubs do not have an O ring seal

Of the three I’ve now fitted, two did. Just sayin’.

Re ABS o-ring - makes sense. Nice touch with the metal gaskets on this one though.

too late?

Originally Posted by ballbag

Of the three I’ve now fitted, two did. Just sayin’.

Re ABS o-ring - makes sense. Nice touch with the metal gaskets on this one though.

as the front and rear bare hubs are identical often an O ring is included for use if fitting on the rear axle. the only diffencence is when you purchase a dedicated hub which includes the sensor wire then they are different part numbers as the sensor wires are different lengths.

Is not 100 kg metre equal tp 980 Newton metre?

Yes

Originally Posted by fitzy

So 100 kg x 1 metre equals how many nm?

You may be confusing Nm with kg.
A 1 kg force is equal to a force of 9.8 Newton, so (your weight of) 100 kg x 9.8 = 980N
Multiply this by the 1.3 meter bar and you get a torque of approx 1300 Nm
No wonder your bearing didn't last. Far too overtight.
For the correct torque, 490 Nm is approx 50 kg (490 divided by 9.8) at 1 metre.
For the 1.3 m bar you would need approx 38.5 kg to provide 490 Nm.

Hope this helps.

First time reply. Second attempt as may have got the first try wrong.

A force of 1kg as equal to a force of 9.8 Newton metre.
So your weight of 100 kg is equivilant to 980 N
Multiply this by your 1.3 metre bar and you have a torque of approx 1300 Nm.
No wonder your bearing failed. Far too much tightening torque.
For a torque of 490 Nm you need a force of 50 kg at 1 metre (490 divided by 9.8 = 50)
With your 1.3 metre bar, you would need to apply a force of 38.5 kg (at 1.3 metre) to give you the correct 490 Nm to tighten the nut.