AFT_B009

to the outer ring only. When pressing the hub into the inner ring, force must only be applied to the hub and the inner ring. For applications that have a magnetic encoder built in for the ABS signal, it is vital that the bearing is installed the correct way around. First, check which side the magnetic encoder is and ensure this side is installed inwards, so that the encoder is closest to the sensor, otherwise it will not function correctly. “On Generation 2, as with all installations, always follow the manufacturer’s instructions and use suitable tools to remove and replace the bearing. In this instance, a puller is required to remove the CV joint, hub and knuckle from the bearing.While installing a new bearing, it is also best practice to check and replace the CV boot, especially on older vehicles or if they have done more than 60,000 miles as this will prevent dust and debris contaminating the CV joint.” Moving onto Generation 3, Jon observed: “Technicians must not use an impact wrench on any of the fastenings of a Generation 3 bearing, as this can cause damage to the bearing/hub assembly. Always use a torque wrench to apply the correct torque value as specified by the vehicle manufacturer, especially on the axle nut to ensure correct pre- load, otherwise it may result in premature failure. “If the bearing has a connected ABS loom, take note of the routing and ensure that when a new bearing is installed, it is mounted and routed in the same way.” Solutions Commenting on First Line’s offering, Jon said: “First Line supplies complete kit solutions which can contain several individual components, such as circlips, nuts, washers, bolts, seals, dust caps etc, all of which enable the technician to complete the repair quickly and efficiently the first time, without the need to purchase additional components.” “However, it’s not just about ensuring all the necessary components are included, but also that the product is of a premium quality, comparable to, or in some cases superior to the OE specification. One example in the First Line range is the FKB1109 front wheel bearing kit for multiple Audi applications, including A4, A6 and Q5. This kit has been improved over the OE specification by enhancing the surface hardening on the bearing face, so it has a greater resistance to wear, which improves product longevity.” Correct Wheel bearings are a safety-critical product that are subjected to considerable driving forces throughout their lifetime, so it is vitally important to install replacements the right way: “When faced with a wheel bearing repair,” said Schaeffler’s Technical Manager Alistair Mason, “techs can be safe in the knowledge that REPXPERT, Schaeffler’s online portal, is there to help. This completely free resource is now also available as a handy app for both iOS and Android devices, including some additional and unique mobile functionality to make it even easier to use.” He continued: “Just one of the free technical documents available to download for free from the REPXPERT portal is the ‘FAG guide to wheel bearings’, which tells technicians everything they need to know about the removal and installation of all generations of wheel hub technology. Best practice examples are given for many vehicles.” Technicians can use the VRM look- up function in REPXPERT to find specific vehicle information. Alistair observed: “Not only will this list the appropriate components, but it will also contain vital information to help carry out an accurate repair, such as service information and manufacturer specifications. In a lot of cases, users will also be able to refer to a step-by- step instruction guide and tooling advice. “While on the topic of tools, many technicians will not be aware that the best way of correctly removing and reinstalling tapered roller bearings is by using a hydraulic standing press, as not applying pressure in the correct places is likely to damage the part and bearing seat – especially if using a hammer.” Generation-specific On tooling, Alistair said: “Generation specific hub tools are available from Schaeffler and all good tool manufacturers, which will help ensure a professional repair. They differ in terms of their use, design and price; for example, a tool with a manually- operated spindle is the economical option but requires a high level of force to operate, whilst the hydraulic option is more expensive but less force is required. “Both designs allow the technician to carry out a professional removal and installation without having to remove the complete steering knuckle and without having to carry out wheel realignment. If the special tools aren’t available, the only option is to remove the steering knuckle and carry out the repair on a hydraulic steering press. As a general rule, wheel alignment is necessary after removing the steering knuckle.” Other tools may also be required for Generation 1 and 2 bearings: “Removal and installation of the wheel bearing in the steering knuckle are not the only important tasks; on certain Generation 1 and 2 wheel bearings, for example, the inner ring must be pulled from the wheel hub, as it remains on the flange during assembly. “An appropriate puller is designed to separate the bearing inner ring from the hub using a spindle. It’s imperative to follow this method, as not doing so could cause damage to the bearing seat or hub.” Alistair added: “Special tools are vitally important during the installation of Generation 2.1 wheel bearings, with two important things to remember: firstly, the pressing force must be applied to the outer ring only and, secondly, the snap ring must be held in position so that it engages correctly into the designated groove in the steering knuckle.” 40 AFTERMARKET SEPTEMBER 2020 BEARINGS Above: Generation 1 bearings from Borg & Beck www.aftermarketonline.net