What Is A Hub Assembly? Why Is It Important?

If you lift your Subaru and then take off one of the wheels, you’ll see the wheel hub assembly. What is it, and why is it important? You’ll learn all about wheel hub assemblies in this guide.

What Is A Wheel Hub Assembly?

Subaru Wheel Hub

The wheel hub assembly is a component that allows the wheel to rotate freely while remaining attached to the car. The wheel hub assembly consists of a hub with a bearing on each side.

The hub assembly slides over the spindle, and is fastened in place with a castle nut. The rotor then slides over the lug studs, and is held in place by the wheel and the lug nuts.

The Components Within A Wheel Hub Assembly

A wheel hub assembly comes with several components:

  • Hub
  • Inner and outer wheel bearings and races
  • Wheel studs (where the wheel goes on and is secured by lug nuts)
  • Seal (keeps water out of the bearings)
  • Dust cap (covers the castle nut)

Why Is The Wheel Hub Assembly Important?

The wheel hub assembly is the component that connects the rotating wheel to the spindle, which is not rotating. All of the forces generated by the tire rolling on the road are passed through the hub to the car. The hub is a very strong, precisely made component.

Why A Broken Wheel Hub Assembly Is Bad News

A wheel hub assembly should last about 100K miles. But it will wear out eventually. When it wears out, it is actually the bearings in the assembly that are worn out. These can be replaced, and the hub itself can be reused. Sometimes the wheel bearings will fail prematurely. The most common causes of a premature bearing failure are:

  • A failed seal
  • Running oversize (heavier) tires
  • Running wheels with a wider than stock offset
  • Poorly maintained brakes that overheat the bearings
  • Driving on rough roads

A failed wheel hub assembly puts you and other drivers at risk. The wheel can no longer turn smoothly. It wobbles slightly as it rolls. If this problem goes unchecked long enough, the steel in the spindle or hub assembly can fracture and cause the wheel to fly off.

Replacing Your Wheel Hub Assembly

OEM Subaru hub

A wheel hub assembly replacement is a straightforward job anyone with the right set of tools can do. The first thing you need to do is to get a replacement wheel hub assembly.

The saying “you get what you pay for” is especially true when it comes to replacement wheel hub assemblies. A lot of aftermarket wheel hub assemblies aren’t made with good quality materials. Because of that, aftermarket wheel hub assemblies are more likely to fail early. OEM is always the safest bet.

At SubaruPartsPlus.com, we offer OEM wheel hub assemblies at wholesale pricing. Get yours today!