During long-term use, semi-trailer axles are inevitably prone to various malfunctions due to complex road conditions, frequent load changes, and other factors. Timely and accurate determination of the cause of the malfunction and adoption of effective troubleshooting methods are crucial for ensuring vehicle safety and improving transportation efficiency. Below, we will provide a detailed introduction to the common faults, causes, and corresponding troubleshooting measures of semi-trailer axles.

1、 Abnormal noise from the vehicle axle

Fault phenomenon

During the driving process of the vehicle, abnormal noise is emitted from the axle, which may be manifested as a continuous "buzzing" sound, intermittent "clicking" sound, or sharp friction sound.

cause analysis

1. Bearing wear: After long-term use, the bearings at both ends of the axle may wear the ball bearings, raceways, or retainers, resulting in poor operation and abnormal noise. In addition, insufficient lubrication, deteriorated lubricating grease, or impurities can also accelerate bearing wear.

2. Loose components: Loose wheel hub bolts, loose bolts connecting the axle and suspension components, causing the components to collide with each other during driving, resulting in abnormal noise.

3. Abnormal gear meshing: For the drive shaft, wear and improper meshing clearance of the main reducer gears can cause noise during operation.

4. Brake component issues: Uneven wear of brake shoes, uneven inner walls of brake drums, or foreign objects mixed between brake pads and brake drums can cause harsh friction sounds during braking.

Troubleshooting

1. Check the bearings: After parking, rotate the wheel hub by hand and feel the resistance to rotation. If the resistance is high or there is obvious jamming, disassemble the wheel hub and check the bearing. Bearings with severe wear should be replaced in a timely manner and refilled with an appropriate amount of qualified lubricating grease.

2. Tighten components: Use a wrench to check the hub bolts, axle and suspension connection bolts, and tighten them to the specified torque. If the bolt has loose threads or damage, it should be replaced.

3. Adjust gear meshing: Check the wear and meshing clearance of the main reducer gears on the drive shaft, and adjust or replace the gears if necessary. The adjustment process requires the use of professional tools and strict adherence to the maintenance manual.

4. Maintenance of brake components: Disassemble the brake drum, check the wear of the brake shoes and brake drum, and clean any foreign objects between the brake pads and brake drum. If the brake shoes are worn to the limit or the inner wall of the brake drum is severely worn, the corresponding components need to be replaced and the brake pads should be ensured to fit well with the brake drum.

2、 Vehicle axle heating

Fault phenomenon

After driving for a period of time, the temperature of the axle parts becomes too high, and touching the axle shell, wheel hub, and other parts with your hands may feel hot and even accompanied by a burnt smell.

cause analysis

1. Poor lubrication: Insufficient, dry or deteriorated bearing grease cannot effectively lubricate and dissipate heat, resulting in increased friction between the bearing and the journal, generating a large amount of heat.

2. Brake drag: The brake clearance is too small, and the brake shoes and brake drums (or brake pads and brake discs) are still in slight contact in a non braking state, causing continuous friction and heat generation. In addition, brake cylinder piston jamming and return spring failure can also cause incomplete release of the brake.

3. Abnormal tire pressure: If the tire pressure is too low, it will increase the driving resistance, causing the axle to bear greater load and leading to heating.

4. Axle deformation: The axle undergoes bending deformation due to significant external impact, generating additional friction and stress during operation, resulting in an increase in axle temperature.

Troubleshooting

1. Improve lubrication condition: Check the condition of the bearing grease. If the grease is insufficient or deteriorated, replenish or replace it in a timely manner. At the same time, clean the lubricating oil passage to ensure that the lubricating grease can smoothly reach the lubrication area.

2. Adjust the brake clearance: Use professional tools to adjust the brake clearance to the specified value, check the movement of the brake cylinder piston, and if the piston is stuck, it can be cleaned or replaced. In case of failure of the return spring, replace the spring in a timely manner to ensure that the braking components can return to their original position normally.

3. Check tire pressure: Use a tire pressure gauge to measure the tire pressure and adjust it to the standard value. Regularly check tire pressure to ensure stable tire pressure.

4. Calibration or replacement of the axle: If the axle is slightly deformed, professional equipment can be used for calibration; If the deformation is severe, a new axle needs to be replaced to ensure the normal operation of the axle.

3、 Vehicle running off course

Fault phenomenon

During the driving process, even if the driver keeps the steering wheel still, the vehicle will automatically shift to one side, affecting driving safety.

cause analysis

1. Inconsistent tire pressure on both sides: The different tire pressures on the left and right sides result in differences in tire diameter and contact area, causing uneven force distribution during vehicle operation and resulting in deviation.

2. Suspension component damage: Steel plate springs that break or deform, air springs that leak, shock absorbers that fail, or suspension connecting components that become loose can all disrupt the balance on both sides of the vehicle and cause driving deviation.

3. Deviation in the installation position of the axle: The axle was not positioned and adjusted strictly according to the standard during the installation process, resulting in inaccurate relative position between the axle and the frame, causing the vehicle to lose control of its direction while driving.

4. Inaccurate wheel alignment parameters: Changes in wheel camber angle, toe in, and other alignment parameters can affect the vehicle's straight-line driving performance, leading to deviation.

Troubleshooting

1. Adjust tire pressure: Check and adjust the tire pressure on both sides to maintain consistency. At the same time, check the tire wear condition. If the tire wear is uneven, it can be swapped or replaced.

2. Maintenance of suspension components: Carefully inspect suspension components such as steel plate springs, air springs, and shock absorbers, replace damaged components, and tighten loose connecting bolts. For air springs, it is necessary to ensure that their air pressure is normal and there is no air leakage.

3. Correct the installation position of the axle: Recheck the installation position of the axle, adjust it according to the vehicle's technical requirements, and ensure that the axle is perpendicular to the frame and symmetrical on both sides.

4. Calibrate wheel alignment parameters: Use professional four-wheel alignment equipment to detect and adjust parameters such as wheel camber angle and toe in to restore them to standard values.

The common faults of semi-trailer axles are diverse, and accurately identifying the root cause of the fault and adopting appropriate troubleshooting methods can effectively solve the problem. If encountering complex faults in practical operation, it is recommended to seek the help of professional maintenance personnel in a timely manner.