NTN SNR has issued some important advice to technicians on fitting Active Sensor Bearings (ASB).

Active sensor bearings have been a feature on cars since the late 1990’s when SNR pioneered the then new technology on the Renault Laguna. They allow for the active measurement of individual wheel speed. The bearings are equipped with a magnetically encoded seal, with a series of north and south poles. A nearby active sensor delivers a digital signal according to the wheel speed, down to zero. This information is then sent to various electronic vehicle systems such as ABS, ESP, HDC, and GPS.    

NTN-SNR ASB now appears on all of the top selling cars in Europe as well as most other European and Asian models. As well as being the leading OE supplier of these components, the company also produces 100,000 ASB bearings per day for the aftermarket.

ASB bearings are fitted in the same way as a conventional types. However, certain extra precautions must be considered in addition to the manufacturer recommended procedure;

• Ensure the knuckle, hub, the press etc. are clean and free from swarf and other metallic particles
• The ASB bearing must be correctly stored, the seal must not be subjected to shocks, or contamination. For protection only remove the plastic cover just prior to fitting.
• The fitting of the bearing must be done with the correct tools for removal and replacement so that the encoded seal is not damaged.
• The bearing must not be placed near to any source of magnetism for example a magnetic screw driver, as it will erase the magnetic poles within the encoder.
• Always install the wheel bearing with the magnetic encoder inboard side, you can check this with a metal paper clip.
• Always follow the vehicle manufacturer's instructions.

To assist with ASB fitting NTN SNR have produced a convenient ASB detector. This allows for quick and accurate identification of the ASB encoded seal and correct positioning relative to the sensor. The SNR ASB detector card is shaped to enable use on all types of ASB equipped bearings.