Metelli, with over 30 years’ experience in the production of transmission components (constant velocity joints and drive shafts), has added the wheel bearing kit to its range. This additional range complements the drivetrain line and completes the selection of products available to customers.
The wheel bearing is a very important safety element asit has to withstand considerable axial and radial stress due to bends, kerbs, acceleration, landslides, rough roads and the weight of the vehicle. The main function of the wheel bearing is to reduce the mechanical friction of the constant-velocity joint that rotates inside the spindle, ensuring that the axle shafts transmit the rotational movement to the wheels correctly, even during steering.
The Metelli Group range includes around 600 codes covering 90% of European car parc.
The range includes all the accessories required for installation (nuts, screes, circlips and split pins). All the bearings are protected and internally lubricated with a specific high-performance grease. Also available with toothed phonic wheels and ABS (Magnetic Encoder) pulse generator rings for maximum braking safety. (there is a specific assembly instruction sheet in the package, to help the mechanic with the installation. The wheel bearings kit of the latest generation are equipped with a multipolar encoder integrated in the seals that transmits the rotation speed signals.
Magnetic encoders use a signal detection system based on the variation of the magnetic flux generated by a magnet rotating in front of the sensor, which is usually fixed to the encoder shaft. The change in the magnetic field is sampled by the sensor and converted into an electrical pulse that defines the position and the type of reading, which may be axial or radial. The advantage of the magnetic system is mainly the absence of contact in the readings, which prevents wear and tear on the device and therefore makes it maintenance-free, meaning it is highly cost-effective and has a potentially infinite lifespan.
The systems that can use the Magnetic Encoder are:
• Anti-lock braking system (ABS)
• Anti-slip regulation (ASR)
• Electronic Stability Program (ESP)
• Dynamic Stability Control ( DSC)
• Vehicle Stability Control (VSC)
• Vehicle Stability Assist (VSA)
• Traction Control (TRC)
• Dynamic traction control (DTC)
• Support system Traction Control System (TCSS)
Their design has changed greatly since they were invented, passing from simple bearings to compact units integrated in the wheel hub to transmit signals to the ABS control units.
1st Generation bearings. These are simple units with single or double ball bearings, pre-lubricated and pre-loaded. Widely used in small to medium-sized vehicles.
2nd Generation bearings. The bearing incorporates a fixing flange on the outer ring, ensuring quick and easy installation. They allow for more compact, lightweight and efficient solutions. Used on the front or rear axles for non-drive wheels
3rd generation bearings. The bearing incorporates one flange to attach it to the brake disc or the wheel and a second flange to attach the unit to the suspension. They are usually equipped with a built-in ABS sensor. This solution allows for significant reduction in weight, noise and vibration.
I Races with a high finish standard
II Rings made of high-grade chromium steel for maximum wear resistance
III Seals: High-efficiency screens with a shaped profile in rubber and special steel
IV Low-friction reinforced nylon cage
V Rolling elements with a high finish standard
VI Steel ring to reinforce the structure and facilitate assembly
Our wheel bearings are designed and developed to provide numerous advantages:
• We use a suitable grease that reducing friction and wear between the rolling elements and the race protecting the bearing from corrosion
• Hardness: adequate hardness of the ring and ball races prevents micro-incisions that generate noise and lead to premature failure.
• Our bearings are designed respecting very precise requirements of tolerances and alignment
• We use the best seals that prevent grease escaping from the bearing and protect the bearing from external contamination.
These advantages allow to guaranteed the following characteristic:
• Precise wheel guidance
• reduced friction, meaning less noise and greater driving comfort
• less weight, resulting in lower CO2 emissions
• high stability
• optimum quality and safety
• a long working life
• thermal stability
• corrosion resistance
• low maintenance
• easy assembly/ disassembly
What can damage a wheel bearing kit?
• Rough road surface
• Adverse weather conditions
• Heavy bumps against kerbs
• Incorrect installation • Bearing assembly defects
• Use of unsuitable tools
• Malfunctioning of wheel drive components
Characteristics symptoms of a defective brake disc:
• Unusual noisiness
• Operating irregularities
• ABS or ESP warning light on
• Vibrations on the steering wheel
• Brake pedal vibration
• Vehicle instability during straight driving (veering)
• Noise when parking or making tight turns at low speed
Product quality is guaranteed by quality and performance tests carried out in a dedicated test room, following strict internal procedures and respecting the following parameters:
• Radial and axial clearance