Why do the rear wheels of a car keep making noises? What should I do when reversing in the rain?

A car has four wheels, front and back. Common driving modes include front-wheel drive, rear-wheel drive and four-wheel drive. Rear-wheel drive is rear-wheel drive. Sometimes the rear wheels make noises while driving. Why is this?

Why do the rear wheels of a car keep making noises?

1. Check the brake pads. It is possible that the brake pads have been worn to the limit, causing the brake pads to rub against the brake drum or brake disc.

2. The bearing is short of oil and the oil seal is aging, causing abnormal noise in the bearing

3. First check whether the car wheel rim is deformed. Look at the outside first, which can usually be seen with the naked eye. It may also be internally deformed. Internal deformation requires removing the wheel and tire to check. If there is deformation, repair it quickly. If the deformation is too serious, it is recommended to replace it with a new one directly.

4. Check the fender to see if there is any friction noise

5. Check whether the disc or brake drum is stuck by small stones, causing friction noise.

6. Check whether the motor has abnormal noise. If it is a high-speed motor, the reduction gear may be damaged internally, causing the noise.

What to do when the rear wheels make unusual noises when reversing in rainy days

Many older vehicles have front disc and rear drum brakes. That is, the front wheels are braked with disc brakes and the rear wheels are braked with drum brakes. Drum brakes are prone to water ingress and retention after car washing or rain. Pulling the handbrake after parking may cause locking and abnormal noises occasionally the next day.

Disc brakes are in direct contact with the air and the outside environment. Although they have good heat dissipation, they are easily worn by small stones. Brake discs are made of gray cast iron. Washing the car on rainy days will cause the brake discs to rust and produce iron filings. The brake discs also move with the wheels and brake through friction. Moreover, the brakes are also in direct contact with the outside environment, so it is inevitable that some tiny impurities will be adsorbed on the brake discs.

Drum brakes are generally used in heavy vehicles with a long braking stroke. Drum brakes brake by friction between the brake shoe and the brake drum to generate resistance. However, friction generates heat, causing the brake shoe to produce fine iron filings. Impurities in the brake drum can cause poor braking and abnormal braking noises.

Are the two rear wheels of the car interchangeable?

Different vehicles have different chassis designs, but they are basically the same. The tires are mounted on the chassis by the suspension system, which reduces the impact of the tires on the chassis and increases the comfort of the vehicle. During the continuous driving of the vehicle, the suspension system will have slight changes, which are generally invisible to the naked eye and can only be seen on a dedicated four-wheel alignment instrument.

If the road condition is not good, it will accelerate the change of suspension system parameters. In severe cases, the deformation of the suspension system can be seen directly. The tires are installed on the suspension system. Changes in the suspension system will cause changes in the contact surface between the tires and the ground. Over time, tire wear will occur. At this time, four-wheel alignment must be done to adjust the suspension parameters to restore them to their original state.

In daily driving, if the road conditions are good, the tires need to be rotated every 20,000 kilometers, which is conducive to uniform wear of the tires and can also appropriately extend the service life of the tires. If the road conditions are relatively bad, the time for rotating tires needs to be shortened. In serious cases, four-wheel alignment is required. If the four-wheel alignment cannot be adjusted, it needs to be repaired.