Schaeffler highlights the importance of quality parts and correct tool use during wheel hub repairs
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 of the very highest quality. As a trusted technical partner and original equipment supplier to vehicle manufacturers around the world, FAG wheel bearings are chosen for their quality, reliability and durability.
Should technicians be faced with a wheel bearing repair, they can be safe in the knowledge that REPXPERT, Schaeffler’s online portal for professional technicians, 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.
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 including:
• BMW 6-Series front (non-driven) axle (tapered roller bearings)
• Renault Clio III front (driven) axle (Generation 1 with ABS)
• Volkswagen Bora rear (non-driven) axle (Generation 2)
• Audi A4 (8K) front axle (Generation 2D)
• Skoda Roomster front (driven) axle (Generation 2.1)
• Volkswagen Golf VI front (driven) axle (Generation 3)
Technicians can use the VRM look-up function in REPXPERT to find specific vehicle information. 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.
Whilst 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 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 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.
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.