Wheel bearings are safety critical parts so garages need to obtain the best possible advice when replacing them on vehicles that enter the workshop.
Schaeffler Automotive Aftermarket (UK) Ltd’s FAG wheel bearings are fitted as original equipment on one in three European cars – a staggering 30 million per year – and consequently the company is an expert when it comes to providing invaluable technical advice and expertise, both bespoke theoretical in literature and also practical, such as the live hands-on demonstrations carried out at events such as the regional MechanEx exhibitions.
The FAG orbitally formed Gen 2 bearing is fitted as original equipment to many popular modern vehicles, including the Ford Focus hatch/estate/saloon, 2004-2011.
At first glance the construction appears simple, a pre-assembled unit consisting of a hub flange combined with a Gen 1 bearing. However, look at the face of the Gen 1 bearing and you will see that the flange has been orbitally formed, which not only retains the bearing, but also allows the specific clearance, clamp loads, and exacting tolerances that the application requires to be pre-set at the FAG factory.
Most of the applications covered by Gen 2 bearings have an encoder seal incorporated into the bearing, which sends a signal to the ECU to allow the activation of on-board safety critical systems such as anti-lock brakes (ABS), traction control (ASR) and electronic stability programmes (ESP).
In the image below you will notice a metal pressing located towards the flange on the bearing. This is a retaining ring which clips into a locating groove in the hub when the bearing is pressed fully home, securing it in place much like a circlip. When the bearing has been fully pressed into the hub it cannot be removed without damaging the retaining ring, so care must be taken to ensure that it is fitted correctly first time.
If you try and fit the bearing by pressing it into the hub using the drive flange you are liable to damage the raceway leading to premature bearing failure. Because of the specific Gen 2 bearing design and the possibility of damage during fitment, a specially designed tool is required to mount the bearing correctly.
The special tool consists of a two-piece collar supplied in a range of sizes to suit different Gen 2 bearings. The fitting tool collar sits in the space between the rear of the hub flange and the retaining ring (see the image below). Once fitted the collar allows all of the force applied to be evenly distributed through the outer race when pressing the bearing into the hub (or knuckle). As well as ensuring safe fitment, another major advantage of using the correct tools is that the hub/knuckle does not have to be removed to allow the bearing to be fitted.
The company has also produced new posters and leaflets which set out the market-leading attributes of its 1st, 2nd and 3rd generation FAG wheel bearings.
The poster includes expert advice on fitting bearings, including fitment of bearings with ABS encoders and ABS sensors. If you would like to receive a leaflet or poster please contact Customer Service on 01432 264264.
More information for exact applications is available at www.schaeffler-aftermarket.com while the fitting tool is available from the company’s stockists.