Wheel hubs are bearings located between the brake drums or discs and the drive axle. It's a crucial part of your steering system contributing to the safe steering and handling of your vehicle. The wheel hub assembly keeps your wheel attached to your vehicle and allows the wheels to freely turn enabling you to safely steer. Comprised of precision- manufactured bearings, seals and sensors in one pre-assembled unit, a wheel hub bearing unit is critical to performance, from the smoothness of the ride, to fuel efficiency, to the integrity of anti-lock braking systems. Hub bearings include the wheel speed sensor that controls the anti-lock braking system. This sensor sends a constant signal to the ABS control system, telling it how fast each wheel is turning. Issues within the wheel hub bearing can cause anti-lock braking systems to malfunction, produce annoying wheel vibration and noise etc.