The failure or damage of shock absorbers will directly affect the smoothness of the vehicle's ride and the comfort of passengers, and it will also impact the lifespan of the vehicle's components. Therefore, the inspection and maintenance of shock absorbers are essential. After driving the vehicle on an uneven road for 10 to 15 kilometers, touch the outer shell of the shock absorber with your hand. If it does not feel warm, it indicates that the shock absorber may have lost its damping effect due to lack of oil or damage to key components, and it should be removed for inspection or replaced with new parts. If abnormal continuous vibrations occur during the vehicle's operation, carefully check if the shock absorber is leaking oil; if it is leaking, it should be addressed. During the secondary maintenance of the vehicle, the working condition of the shock absorbers should be checked. The inspection method is: fix the lower end of the shock absorber in a vice, and stretch and compress it several times by hand. A normal shock absorber should have a certain damping force, and the resistance when stretching should be greater than the resistance when compressing. If it is unstable or has no resistance, it may be due to lack of oil or damaged components, and it should be repaired or replaced with new parts.

When a beautiful new car enters the family, natural elements such as acid rain, storms, humidity in the atmosphere, and salt are constantly eroding your beloved vehicle. This is especially true in coastal cities where the warm, humid marine climate combined with salty sea breezes, like in areas such as Yantian and Meisha in Shenzhen, leads to frequent traffic from seafood trucks and water tankers selling seawater. The leaking seawater acts like a layer of salt sprinkled on the road, and vehicles that inadvertently follow the same path are corroded. These factors can exacerbate the rusting of cars. After applying rust prevention, it is like adding an extra layer of protective film to your beloved car, effectively resisting the erosion of these adverse factors and delaying the aging of the vehicle. As time goes on and the car continues to operate, the rust prevention layer on the chassis (especially at the wheel hubs) gradually thins and peels off due to the impact of sand and gravel, while the galvanized layer of the chassis is gradually damaged, leading to rusting of the vehicle. If you go to a professional rust prevention center for treatment, the center will repair the car's chassis every year to ensure the thickness of the rust prevention layer.

In mainland China, after recommendations from automotive beauty and decoration businesses and extensive reports from automotive media, many new car owners know that they should install anti-theft devices, apply explosion-proof heat insulation films, seal the glaze, and modify the interior after buying a car. However, experienced car owners will tell you, "If the car is going to deteriorate, it will start from the bottom." The first priority after buying a new car should be to perform chassis protection work. Chassis protection work includes chassis sealing and chassis armor, which first emerged in the south but has not been widely promoted. In the past two years, the number of private cars in the country has surged, and car owners cherish their vehicles very much, which has led to the popularity of these two businesses. However, apart from Beijing and Shenzhen, car owners in other cities, including Shenyang, the fourth largest private car market, are still unfamiliar with this.

Sealing and armor are fundamentally different. 　

Chassis sealing is a maintenance project that many car owners are familiar with. Its main function is to protect the exposed steel plates of the car's chassis from stone impacts and corrosion. However, many car owners still feel uneasy when they hear the sound of gravel hitting the chassis. To isolate the noise generated by sand and stones hitting the chassis, chassis armor is necessary. In addition to having the two functions of sealing, chassis armor also has significant sound insulation and noise reduction effects, as it forms a nearly half-centimeter thick coating of rubber and polyester material on the chassis after application. This coating has high elasticity and effectively reduces the noise generated when gravel hits the metal directly.

In addition to different functions, the thickness and physical composition of the two also differ. Ordinary sealing has a construction thickness of 2 millimeters, with the main component being polyester material, while chassis armor is a mixed formula of rubber and polyester material, with a construction thickness of 4 millimeters, and some areas exceeding half a centimeter. Applying armor and sealing does not conflict; the most comprehensive protection measure is to do both, allowing car owners to gain double peace of mind. The price of armor is slightly higher, with market prices ranging from 1500 to 1800. Depending on the size of the vehicle and whether any treatment is done, the price may fluctuate slightly. New car armor will yield a more effective result, and the process is simple, so the price will be slightly lower. However, for old cars that have never undergone chassis treatment, the price of armor will be slightly higher.

Why should chassis armor be applied? 　

In summer, the scorching heat of the ground, the invasion of acid rain, and the impact of flying stones on gravel roads, especially the corrosion from de-icing agents on snowy roads in winter, can leave even the strongest steel frames scarred. Most mid-range cars popular today have very simple chassis treatments due to manufacturers' cost considerations. Many cars only have a thin layer of underbody coating sprayed on, and some models only have partial spraying, while domestic cars are almost never sprayed. Under normal climate and geographical conditions, the original factory rust prevention measures can provide limited protection for the chassis, but they cannot cope with abnormalities. For example, the chassis of the Jetta, which has been continuously decreasing in price, has not been treated, while the underside of the Vios has only been sprayed 10 centimeters wide, and after cleaning, the entire underside is gone.

What kind of cars need chassis armor? Mercedes-Benz, BMW, and Audi, Passat, and Bora produced by FAW-Volkswagen and Shanghai Volkswagen already have relatively complete chassis protection measures when they leave the factory, so there is not much necessity for new cars to apply chassis armor. However, other cars priced below 200,000 to 150,000, especially domestic and Korean cars, should definitely apply it.

How to apply chassis armor? 　

Chassis armor is applied in two steps: first, cleaning. The vehicle is lifted using a lift, and a cleaning agent is used to clean the chassis, removing mud, oil, and other debris to expose the original metal surface. Second, a layer of elastic protective coating is sprayed onto the chassis. This spraying can be done multiple times or in one go. Multiple sprayings are relatively labor-intensive but cure faster. One-time spraying is more convenient but cures slowly, with the actual effect being the same. After spraying, it is essential to wait until the surface is dry, meaning it is no longer sticky, before driving the car away. It takes about 4 hours to reach the surface dry state.

The world-renowned brand Henkel from Germany has launched the water-based green environmental product Teleson 2000, which has excellent wear resistance, permanent elasticity, and good noise reduction characteristics. It is the chassis rust prevention technology specified for use by Audi, Passat, and other cars, and it only provides a 2-year quality guarantee. Therefore, for those who want to protect their beloved car thoroughly, one must not be careless and should avoid those chassis rust treatments that only cost a few hundred yuan. Some unregulated maintenance shops use domestic underbody coatings that are generally solvent-based, do not meet environmental protection requirements, and can cause certain corrosive effects on the metal surface of the car's underside. Additionally, during construction, there can be significant harm to the health of the workers. Their adhesion also does not meet standards, and over time, they will peel off, failing to provide the desired protective effect.

When it comes to car maintenance, chassis care is often overlooked by drivers. However, its importance becomes evident in winter or wet conditions. To maintain the chassis in winter, thorough cleaning and rust prevention treatment are necessary, as it provides excellent protection for your vehicle. First, the chassis must be thoroughly cleaned. If there is too much dirt on the chassis, a degreasing cleaner should be used to wash it, revealing its original "color" so that rust prevention care can begin. In a professional beauty shop, the car can be lifted onto a lift for chassis cleaning and wiping, followed by rust prevention care. It is important to wait until the moisture on the chassis is completely dry before proceeding with rust prevention care. During the care process, ensure an even spray coating to form a durable and uniform rust prevention layer. After completing the work, allow for 5 to 10 minutes of natural air drying to finish the chassis rust prevention treatment.

Completing professional chassis care does not mean it is foolproof. There is a common misconception that when people wash their cars themselves, they add some cleaning agents. Please be careful not to use alkaline cleaners, laundry powder, or similar products to wash the car body and chassis, as this will affect the rust prevention effect and shorten the duration of rust protection.

It is recommended to go to a professional beauty shop for chassis care. A simple method to test the quality is to see if the chassis, after rust prevention care, does not hold water droplets when rinsed with high-pressure water. Such an effect indicates genuine care and provides excellent rust protection.

Universal engine oil for gasoline and diesel engines refers to a type of internal combustion engine oil that can be used as both gasoline engine oil and for fleet and military use. Currently, domestically produced universal internal combustion engine oils for gasoline and diesel engines include SD/CC, SE/CC, SFCD, SH/CF, etc. Using universal internal combustion engine oil can simplify the variety of engine oils, and from a practical perspective, the simplification of varieties also brings convenience and benefits in aspects such as oil blending, storage, and transportation.

For front-wheel drive vehicles (FF transmission), the drive shaft uses constant velocity universal joints, which are sealed with rubber boots. If the rubber boot is damaged, sand and gravel can enter the universal joint during driving, accelerating wear and shortening its lifespan. Therefore, it is important to regularly check if the rubber boot is cracked. The signs of a cracked rubber boot are very obvious: there will be a very viscous oil stain (this oil stain is grease) near the wheel rim and engine underbody. If a "popping" sound occurs when the steering wheel is fully turned while driving, it indicates that the universal joint is damaged and should be replaced. It is recommended to frequently check the rubber boot and avoid turning the steering wheel while the vehicle is stationary (as this can cause excessive load on the universal joint, shortening its lifespan).

For rear-wheel drive vehicles, the drive shaft uses two non-constant velocity universal joints. If the driver hears a "clunking" sound from under the vehicle when releasing the clutch to start, or during rapid acceleration or deceleration, it indicates that the non-constant velocity universal joints need to be replaced. A static inspection method is to grab the center of the drive shaft from underneath the vehicle and shake it left and right. If the rotation angle is too large (over 45 degrees), it indicates that the gap of the non-constant velocity universal joint is too large and needs to be repaired.

First, pay attention to the break-in period of use. This is the foundation for extending the engine's lifespan. Whether it is a new engine or one that has been overhauled, it must be broken in according to specifications before it can be put into normal operation. Secondly, regularly check the fastening parts. Diesel or gasoline engines are affected by vibrations, shocks, and uneven loads during use, which can cause bolts and nuts to loosen. Additionally, the adjustment bolts in various parts should be carefully checked to prevent damage to components due to loosening. The valve clearance, timing phase, fuel supply advance angle, injection pressure, and ignition timing should all be checked and adjusted in a timely manner to ensure that the engine is always in good technical condition, which can save fuel and extend its lifespan. Furthermore, maintain clean oil, clean water, clean air, and a clean engine body. If the fuel is not pure, it can cause wear on precision mating parts, increase the clearance, lead to oil leaks, reduce supply pressure, increase gaps, and even cause serious failures such as oil line blockages or bearing burns. If there is a lot of dust in the air, it will accelerate the wear of the cylinder liner, piston, and piston rings. If the cooling water is not pure, it will increase scale in the cooling system, hinder engine heat dissipation, worsen lubrication conditions, and cause severe wear on components. If the exterior of the engine body is not clean, it will corrode the body and shorten its lifespan. Ensure sufficient oil, water, and air. If the supply of gasoline and air is not timely or interrupted, it will lead to difficulties in starting, poor combustion, power reduction, and abnormal engine operation. If the oil supply is insufficient or interrupted, it will lead to poor lubrication, severe wear on components, and even bearing burns. If the cooling water is insufficient, it will cause the engine temperature to rise, power to decrease, and wear to increase, reducing its lifespan. In addition, observe and check frequently, promptly eliminate faults, and regularly perform maintenance on the engine to keep the machine operating in good technical condition.