When installing the first generation of automotive wheel hub bearings, special attention should be paid to tool preparation, vehicle fixation, component disassembly, bearing disassembly and assembly, cleaning and lubrication, pre tightening adjustment, component reset, and environmental and operating standards. Specific precautions are as follows:
1. Tool and equipment preparation
Ensure that the lifting machine, wrench, screwdriver, socket, puller, press machine, clamp and other tools are complete and in good condition. If there is a lack of specialized tools, newly removed waste bearings can be used instead of pads for installation.
2. Vehicle fixing and component disassembly
Drive the vehicle onto the lift and secure it safely, remove the front wheels to expose the work area.
. When removing the half shaft nut, another person needs to step on the brake pedal to provide reverse torque to prevent the half shaft from rotating.Separate brake and steering system:
Remove the brake caliper and hang it on the vehicle body to avoid force on the brake pipeline.
. Remove the ball nut of the steering rod and use ball pliers to separate the steering knuckle from the steering rod. Remove the connecting bolts between the steering knuckle, shock absorber, and lower swing arm.III. Bearing Disassembly and Installation
Disassemble old bearings:
Use special tools or sleeves 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 on the wheel hub.
Use clamp pliers to remove the positioning clamps on both sides of the steering knuckle bearing seat hole.
. Use a press and circular pads to press the old bearing vertically out of the steering knuckle, avoiding tilting.Install new bearings:
Clean the bearing seat holes on the steering knuckle to ensure that there are no impurities, dirt, or old lubricating grease.
.Apply special lubricating grease fully to the seat hole to facilitate the installation of new bearings and reduce wear.
.Install the outer retaining spring of the steering knuckle to position the new bearing.
Use the old bearing outer ring as a cushion block and press the new bearing vertically with a press to ensure that the outer ring is evenly stressed.
. After the bearing is fully pressed in, install the other side retaining spring.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.
.Fourth, Pre tension Adjustment and Inspection
Pre tension Adjustment:
Some car models require adjusting the pre tension of the wheel hub bearings by rotating the wheel hub and tightening the adjustment nut to the specified range (if tested with 200-300 Nm of force, the wheel hub can rotate slightly and stop).
. Rotate the wheel hub 2-3 times left and right, gradually loosen the adjustment nut until only 10-25 Newtons of force is needed to make the wheel hub rotate.Check installation status:
Rotate the wheel hub to confirm that it rotates smoothly and without any abnormal noise.
. Check if the oil seal is intact to prevent impurities from entering the interior of the bearing.Fifth, Component Reset and Tightening
Install the steering knuckle, brake caliper, steering rod and other components in the reverse order of disassembly.
.Strictly tighten the bolts according to the torque specified in the vehicle maintenance manual:
Connecting bolts between the steering knuckle and the lower swing arm: 35 N · m.
Connecting bolt between steering knuckle and shock absorber: 95 N · m.
Bottom nut of steering rod: 35 N · m.
Install the self-locking nut at the end of the half shaft and tighten it to the specified torque (such as 265 N · m). If necessary, ask others to assist in providing reverse torque.
.VI. Environment and Operating Standards
Environmental Cleaning: Before installation, ensure that the working environment is dry and dust-free, and that the tools are clean and free of impurities to prevent particles from entering the bearings and shortening their lifespan.
.Avoid knocking: Under no circumstances should the bearing be struck with a hammer to avoid damaging the raceway or seat hole and causing early failure.
.Magnetic coding ring protection: If the bearing is equipped with an ABS magnetic coding ring, it should be kept away from the magnetic field (such as electric tools), and the magnetic side should be ensured to face the inside of the wheel during installation.
. Paired replacement: Due to similar working conditions, even if only one of the front wheel hub bearings is damaged, it is recommended to replace them in pairs to ensure balance.