Maintenance of hub bearings

Before disassembling the hub, it is necessary to complete the preparations for hub maintenance. Park the vehicle safely and raise the axle to ensure the safety of the maintenance operation.
(1) Remove the decorative cover and dust cover of the hub axle head.
(2) Remove the tire nuts and the tire. Be careful not to damage the threads of the tire bolts. If it is a disc brake, remove the brake first, then remove the lock ring or lock pin by reversing the process.
(3) Use special tools to remove the hub.

(4) Remove the old lubricating grease from the bearings, the shaft necks, and the hub cavities. Clean the hub bearings and the shaft necks with a cleaning agent and dry them with a cloth. Finally, wipe the inner cavity of the hub clean with a cloth.
(5) Check the hub bearings and the bearing rings. If there are cracks, fatigue spalling, or loose bearing rollers, replace the bearings. If there are spots on the bearing rings, also replace the bearings.
(6) Check the fit between the inner diameter of the bearing and the shaft neck. The fit clearance should not exceed 0.10mm. When measuring the shaft neck, measure at the two vertical positions on the ground (this is the area with the greatest wear). If the fit clearance exceeds the specified service limit, replace the bearings to restore the normal fit clearance. Do not use scratches or spots on the shaft neck to reduce the clearance.
(7) After all the parts meet the requirements, apply lubricating grease to the inner bearing and insert it into the hub.

(8) When applying lubricating grease to the inner cavity of the bearing, be sure to squeeze the grease into the bearing until it emerges from the other side. Apply a thin layer of lubricating grease in the hub cavity and the bearing head cover to prevent rust. Avoid applying too much lubricating grease in the hub cavity; otherwise, it will affect heat dissipation and braking.
(9) Install the hub and the outer bearing onto the shaft neck. Use your hands to tighten the shaft head adjustment nut, then use the shaft head wrench to tighten the adjustment nut according to the specified torque. After tightening the nut, rotate the hub several times to check the installation of the bearing; at the same time, rotate the hub to ensure the correct fit between the bearing and the seat ring. At this point, the bearing is properly tightened, and the wheel can rotate freely without feeling any axial clearance.
(10) Finally, install the lock plate, fixing nut, tire, dust cover, and decorative cover, etc., in sequence.

(11) After adjusting the hub bearings, drive for a certain distance (about 10 km), then stop and inspect. Use your hand to feel the temperature of the hub. If it is hot, it is caused by the bearings being adjusted too tightly. In this case, they should be retightened.