Old drivers can easily feel whether the chassis of this car is tight or loose when driving. Usually the newer the car, the tighter the chassis. After a period of use, the chassis will gradually loosen. I believe that car owners have this feeling more or less, but few people know the reason.

Then, let's simply analyze why the chassis will loosen after driving for a long time. The reason why the automobile chassis can form a perfect buffer and ensure the better comfort of the automobile under bumpy road conditions is because there is a rubber buffer at the joint besides the shock absorption system.

Rubber sleeves are usually used to avoid direct friction and collision between metals, and some high-end models also use hydraulic bushings. Chassis is not only the bottom steel plate for stepping on, but also the load-bearing cage of most household scooters. The body frame and chassis of this structure are integrated, so the rigidity of the overall structure will inevitably affect the driving experience.

One effect is that the body will "distort" during exercise. When the car turns at high speed or runs on the bumpy road, the frame and chassis will be twisted to some extent, but this is within the allowable range, that is, it does not exceed the limit force of resistance.

The steering rod and steering knuckle are connected together through the steering rod ball head, which is embedded in the ball head seat, with only a layer of grease in the middle, and the outer surface is protected by a rubber sleeve to prevent grease loss. When turning the steering wheel, the steering knuckle will be pushed by the ball head of the steering rod to move in the ball head seat, and the direction can be moved left and right.

It is inevitable to scratch the rubber sleeve when driving. Grease will be lost after scraping, resulting in "dry grinding", abnormal sound and falling off between the ball head and the ball head seat. The most obvious fault phenomenon is that the steering wheel rotates slightly from left to right, so the ball joint of the steering gear pull rod needs to be considered.

Or gear with abnormal clearance between steering column and steering gear. In addition to abnormal conditions, normal wear will also loosen, which will lead to steering wheel jitter in severe cases. Generally speaking, the chassis adjustment of new cars is very tight and tough, but after a long time, it will feel very loose. On the one hand, there is space, which has a lot to do with it. If you walk in a place with poor road conditions for a long time, the relatively large road bumps will lead to uneven chassis during driving, especially at the joints, such as chassis suspension, which will cause relaxation and lead to poor driving.

It looks loose, which is one of the reasons. It feels like you screw a screw and a bolt together and then fall off every day. Over time, no matter how tight it is, it is loose. With the increase of automobile mileage, many parts of automobile chassis will age and wear.

Especially when the car runs on the uneven road surface, the weight of the car will tilt because of the unevenness of the road surface, resulting in the greater the weight borne by a part of the car chassis, the parts of the car chassis will be deformed, worn and loose, so the car chassis will feel loose after driving for a long time.

In a word, the rubber parts of the chassis will age after the car is used for a long time, and there will be rubber parts between most metals of the chassis to play a buffering role, thus reducing vibration and noise. There are rubber sleeves in the swing arm, stabilizer bar and tie rod in the suspension. However, after long-term use, rubber parts will definitely age, lose elasticity and even crack, resulting in reduced buffering capacity, looseness and abnormal sound. The solution is to regularly check the wear and tear of the rubber parts of the chassis, reasonably replace the wearing parts and aging problems, but the most important thing is to develop good driving habits.

Some car owners are not gentle at all. They don't care when they encounter speed bumps or low-lying roads. And when parking, their cars are parked on the uneven road. Over time, the aging of these parts will naturally accelerate.