Maintenance methods for the first generation of automotive wheel hub bearings

The maintenance of the first generation of automotive wheel hub bearings should revolve around regular inspection, cleaning and maintenance, lubrication management, standardized operation, and environmental protection. The specific methods are as follows:

1. Regular inspection and cleaning

Appearance and internal inspection

After disassembling the bearings, thoroughly clean them with kerosene or gasoline, observe whether there is peeling, pitting, or cracking on the inner and outer raceway surfaces, and whether the rolling elements (steel balls/rollers) and cages are worn.

Check the fit clearance between the inner diameter of the bearing and the shaft neck. The clearance should be ≤ 0.10mm (measured at two vertical positions on the ground). If it exceeds the limit, the bearing needs to be replaced.

. If you hear a buzzing or creaking sound from the wheels or abnormal heating of the wheel hub while driving, you need to stop and check immediately.

Cleaning steps

Remove the wheel hub and axle head decorative cover, dust cover, and remove the tire nut and tire (to avoid damaging the threads).

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The disc brake needs to be disassembled first, then the locking ring/locking pin should be removed, and the wheel hub should be removed.

. Scrape off the old lubricating grease from the bearings, shaft necks, and wheel hub cavities, clean them with neutral cleaning agents or diesel, and then dry them.

2. Lubrication Management

Lubricating grease selection

Use high-temperature resistant lubricating grease such as lithium based grease to ensure uniform filling of the bearing cavity (occupying about 50% of the gap).

. 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.

Replacement cycle

At least every six months or every 10000 kilometers, thoroughly replace the lubricating grease and conduct a comprehensive inspection of the bearings.

. After entering water or dusty environments, the cycle should be shortened to prevent moisture/impurities from entering.

III. Standardized Operation and Installation

Installation Steps

Clean the environment and prevent small particles from entering the bearing.

. After applying new lubricating grease, place the inner bearing into the hub and reinstall the outer bearing and hub to the journal.

Tighten the shaft head adjustment nut by hand, then use a wrench to tighten it to the standard torque, rotate the wheel hub to make the bearing and seat ring fit correctly, and finally retract the adjustment nut to the appropriate angle (ensuring that the wheel rotates freely without axial clearance). The torque requirements vary greatly among different vehicle models, and it is necessary to follow the instructions to avoid being too tight (causing heating) or too loose (causing vibration).

Driving habits

Drive smoothly, avoid sudden braking/acceleration, and reduce bearing impact loads.

. The vehicle load must be within the rated range, overloading will accelerate bearing wear.

When encountering muddy or flooded roads, reduce the speed to avoid prolonged immersion and prevent water from rusting the bearings.

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4. Environmental Protection and Sealing

Dust Prevention and Sealing

Dust environments (such as mines) need to shorten inspection cycles and upgrade dust covers if necessary.

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Ensure that the magnetic thrust ring inside the sealing ring is not subjected to external forces (such as magnetic field collisions), and be installed away from strong magnetic environments.

. After installation, observe the ABS warning needle through a road test to confirm that the bearing function is normal.

Replacement suggestion

When the bearings are damaged, it is recommended to replace them in pairs (replace both left and right wheels 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.