When installing the first generation of automotive wheel hub bearings, it is important to pay attention to eight core issues: tool preparation, component inspection, cleaning and lubrication, installation operation, direction control, tightening torque, encoder protection, and trial operation inspection. The specific details are as follows:
1. Tool and equipment preparation
Special tool replacement plan
If there is no special press, newly removed waste bearings can be used as substitutes, but the size must be completely matched.
Prepare snap pliers, pullers, presses, and circular pads. Comprehensive maintenance companies can use sleeves to replace some specialized tools.
.Lift and secure
Drive the vehicle onto the lift and secure it securely. After removing the front wheels, remove the self-locking nut at the end of the half axle (another person needs to step on the brake pedal to provide reverse torque).
.2. Component Inspection and Cleaning
Shaft and Bearing Seat Inspection
Check whether the shaft and bearing seat are worn or deformed. Minor damage may cause fitting problems and premature bearing failure.
. Clean the bearing seat holes on the steering knuckle to ensure there are no impurities or dirt, and to prevent particles from entering the interior of the bearings.Dismantling of old bearings
Use a special tool or sleeve to push the wheel hub out of the steering knuckle, and the inner ring of the bearing will fall off with the wheel hub.
.Use a puller to remove the inner ring of the bearing, use a clamp to remove the positioning clamp, and use a press and pad to press out the old bearing.
.III. Installation Operation Specification
New Bearing Positioning
Install the outer retaining spring of the steering knuckle to position the new bearing.
. Use the old bearing outer ring as a cushion block, press the new bearing into the steering knuckle, and ensure that the inner ring is not subjected to force; Install the other side retaining spring after pressing in.Use the old bearing inner ring as a cushion block, press the wheel hub into the bearing, and ensure that the inner ring is evenly stressed.
.Avoid violent assembly
It is strictly prohibited to use a hammer to strike the bearing or seat hole to prevent deformation or damage.
. When operating the press, pay attention to the bearing status to avoid deflection or abnormal resistance.IV. Direction and Encoder Protection
ABS Magnetic Encoder Direction
If the bearing is equipped with an ABS magnetic thrust ring, the side with the magnetic ring should be pointed inward, facing the ABS sensitive component.
.When the direction is uncertain, use a light small object close to the edge of the bearing to test the magnetic adsorption position.
.Stay away from the magnetic field before installation to avoid the polarity change of the encoder affecting the ABS signal.
. Sealing maintenanceDo not disassemble the wheel hub bearing or adjust the sealing ring to prevent water or dust from entering and damaging the inner raceway.
.Fifth, Tightening Torque Control
Tighten bolts and nuts
Tighten components according to standard torque values:
Three bolts connecting the lower arm and the steering knuckle: 35N · m
Two bolts connecting the steering knuckle and the shock absorber: 95N · m
Lower end nut of the steering rod: 35N · m
Brake caliper and steering knuckle bolt: 25N · m
Half shaft end self-locking nut: 265N · m
Tire bolt: 110N · m
Use a torque wrench Operation to prevent parts from being damaged due to excessive torque or loose due to insufficient torque.
6. Lubrication and grease addition
Sealed bearings are maintenance free
Modern car wheel hub bearings are mostly designed for sealing, and the interior has been filled with special lubricating grease, so there is no need to add additional grease.
.Lubrication of non sealed bearings
For non sealed types such as double row tapered roller bearings, lubricating grease should be added during installation, accounting for 50% of the bearing clearance to avoid excessive leakage.
.7. Trial operation and inspection
After installation, check
Rotate the wheel hub to confirm that there is no jamming or abnormal noise, and check whether the oil seal is intact.
. Observe the ABS warning needle on the dashboard and verify the encoder function through road condition testing.Regular maintenance
When driving a rear wheel drive vehicle for 38000 kilometers, lubricate the front wheel hub bearings.
. When replacing the brake system, check the bearings and replace the oil seal.