The maintenance of the first generation car wheel hub bearings should revolve around cleaning inspection, lubrication management, installation adjustment, regular maintenance, and standardized use. The specific steps and points are as follows:
1. Cleaning inspection: thoroughly clean and observe carefully
Disassemble the bearings
Place the vehicle on a lift to ensure safety before lifting the axle. Remove the wheel hub and axle head decorative cover, dust cover, and remove the tire nut and tire (pay attention to protecting the threads).
The disc brake needs to be disassembled first, then the locking ring/locking pin should be removed, and finally the wheel hub should be removed with a special tool.
.Clean bearings
Use kerosene or gasoline to thoroughly clean bearings, shaft necks, and hub cavities, removing old grease and impurities.
.Use neutral cleaning agent or diesel for secondary cleaning, wipe dry and inspect:
Inner and outer raceway surfaces: observe for peeling, pitting or cracks.
. Rolling elements (steel balls/rollers) and cages: Check for wear or deformation. Sealing ring: Confirm that there is no damage to prevent impurities from entering.Check the fit clearance
Measure the fit clearance between the inner diameter of the bearing and the shaft neck, and the standard value should be ≤ 0.10mm (measure the shaft diameter at two vertical positions on the ground).
. If the clearance exceeds the limit, the bearing needs to be replaced, and it is forbidden to forcibly reduce the clearance by deburring or pockmarking.2. Lubrication Management: Choose the right grease and apply it in moderation
Choose lubricating grease
Prioritize using high-temperature resistant grease such as lithium based grease to ensure high temperature resistance, wear resistance, and waterproof performance.
. Sealed bearings do not require frequent replenishment, but the grease condition needs to be checked every 50000 kilometers; Non sealed bearings (such as double row tapered roller bearings) need to be regularly refilled.Apply lubricating grease
Apply evenly: Use a grease gun to squeeze the grease into the bearing cavity until it overflows from the other side.
.Control dosage: The amount of lubricating grease in the wheel hub cavity should not be too much (about 50% of the gap) to avoid affecting heat dissipation and braking performance. Rust prevention treatment: Gently apply a layer of lubricating grease to the hub cavity and shaft head cover to prevent rust.
III. Installation and Adjustment: Precise operation to ensure moderate tightness
Installing bearings
Apply lubricating grease to the inner bearing and place it in the wheel hub, then reinstall the outer bearing and wheel hub to the journal.
.Tighten the shaft head adjustment nut by hand, and then use a wrench to tighten it to the standard torque (torque requirements vary greatly among different vehicle models, please refer to the instruction manual).
.Rotate the wheel hub several times to check if the bearing and seat ring fit smoothly, ensuring that the wheel rotates freely without axial clearance.
.Adjust the clearance
Excessive clearance: Bearing shaking, affecting maneuverability.
.Insufficient clearance: Increased bearing wear and reduced service life.
.After adjustment, drive for about 10 kilometers, stop and touch the wheel hub temperature. If it heats up, the nut needs to be readjusted to reduce the tightness.
4. Regular maintenance: Check according to mileage/time to shorten the cycle of harsh working conditions
Regular inspection
Mileage/time: It is recommended to check every 20000 to 30000 kilometers or every 1-2 years.
. Adverse working conditions: After entering water or dusty environments, the cycle should be shortened to prevent moisture/impurities from entering.Replace bearings
If the bearings have cracks, fatigue peeling, loose rollers, or excessive fit clearance, they need to be replaced in pairs (both left and right wheels need to be replaced at the same time) to avoid balance problems caused by one-sided wear.
. When replacing the brake system, check the bearings synchronously and replace the oil seal.5. Standardized use: Drive smoothly, avoid overloading
Driving habits
Drive smoothly, avoid sudden braking/acceleration, and reduce bearing impact loads.
. Regularly check the tire pressure and adjust it in a timely manner. Excessive or insufficient pressure can accelerate bearing wear. Road condition responseWhen encountering muddy or flooded roads, reduce the speed to avoid prolonged immersion and prevent water from rusting the bearings.
. Dust environments (such as mines) need to shorten inspection cycles and upgrade dust covers if necessary.