What does the driver often mean by 'divergent' chassis? What components should be repaired?
The meaning of chassis divergence is that when the vehicle is driving on bumpy roads, the chassis feels like it is about to break apart, making a strange noise. The car shakes severely, and the direction is unstable. The car does not look like a whole and does not give a sense of heaviness and tightness.
The meaning of chassis divergence is that when the vehicle is driving on bumpy roads, the chassis feels like it is about to break apart, making a strange noise. The car shakes severely, and the direction is unstable. The car does not look like a whole and does not give a sense of heaviness and tightness. The divergence phenomenon is generally particularly evident on older cars, and the older the car, the more obvious the divergence phenomenon will be. This is mainly due to aging and looseness of some components of the vehicle chassis. Finding the cause and conducting maintenance can significantly improve it. It's just that many car owners are unwilling to spend too much money on repairing their old cars, and the comfort is just a bit poor. Today, let's talk about which components on the chassis are aging or damaged, which can cause divergence. Targeted maintenance can also significantly improve the phenomenon of divergence without spending too much money.
1. The chassis screws are loose, commonly the large screws that fix the Yuanbao beam are loose. The Yuanbao beam, also known as the subframe, connects all components on the front chassis and the engine gearbox to the Yuanbao beam. The screws here are loose, and when driving on bumpy roads, the entire chassis components will shake and rub against each other, making a noise. It is certain that the chassis is not compact and feels like it needs to be disassembled. Simply tighten the screws to solve the problem. Other large screws on the chassis may also feel loose, but the probability of other screws loosening is not high. As long as they have not been disassembled, they generally do not loosen. If the torque for disassembly and installation is not enough, loosening may also occur. Loose screws will definitely make a strange noise. The inspection and maintenance method is to tighten all important screws on the chassis, and the maintenance experience here is quite important.
2. Aging of rubber components. The aging of all rubber components on the chassis can cause a sense of looseness in the chassis, and the phenomenon of divergence in older cars is often the most closely related to the aging of rubber components. The common ones are the two rubber sleeves of the triangular arm and the rubber sleeves of each stabilizer bar, which are often broken and the easiest to see components. The rubber sleeve is a rubber component that will inevitably age over time. After aging, it will become stiff and inelastic, which greatly reduces the buffering capacity of the vehicle when driving on bumpy roads. It is normal for abnormal noises and looseness to occur. Because the main function of the rubber sleeve is to cushion, increase the thickness of the chassis, and reduce noise. The general inspection method is to observe with eyes. Many small cracks appear on rubber components, and some may even crack as a whole. Oil leakage from buffer blocks with hydraulic oil indicates aging of the rubber sleeve. Generally speaking, vehicles older than seven or eight years old will experience aging of rubber components, with some being light and some being heavy.
3. Each ball head is loose. The loose ball joints on the triangular arm, the inner and outer ball joints of the steering gear lever, and the ball joints on the stabilizer bar can also cause the chassis to diverge. The loose ball joint means that the gap is too large. Under normal circumstances, whether on bumpy roads or braking, they can firmly connect the corresponding components and will not move or collide with each other. If the gap is too large and the road is bumpy, the ball head will shake left and right, making the car unstable and even making a noise. Especially some small stabilizer ball heads are not easy to attract attention. The method to check the looseness of the ball head is usually to shake it with your hands. If it is not loose, you will not feel the gap, which means it cannot shake. If it is already loose, there will be obvious gaps. In addition, there is lubricating grease on the ball head and a ball cage sleeve wrapped externally. If the ball cage sleeve is damaged, it should also be replaced in a timely manner. If not replaced, the ball head will soon be damaged.
4. The shock absorber is damaged. The common damage to shock absorption is oil leakage, and the top glue on the upper part can also be damaged. When there is an oil leak, there is usually no feeling of a broken frame, but rather a feeling of severe shaking of the car, frequent bouncing on bumpy roads, and an unstable and light feeling. This is because the shock absorber has failed due to oil leakage. When the spring jumps, it cannot be effectively pulled and can only be allowed to jump. The inspection method is to observe with the eyes, and there is no need to disassemble any components. If there is fresh oil leakage on its surface, it indicates that its lifespan has reached. If there is no fresh oil leakage, it indicates that it is normal. In addition to unstable bumps, the top glue also makes abnormal noises when it is damaged. As long as there is a abnormal noise on the upper part of the shock absorber, it is mostly caused by the top glue being damaged.
The common causes of chassis divergence are the above four situations, involving a large number of components, especially the rubber sleeve and ball joint, which need to be checked for each. If the chassis of a very old car is loose, it may not be caused by a problem in one place, but often due to multiple reasons, requiring a comprehensive inspection. Fortunately, most of the replaced parts are rubber parts, and the material cost itself is not high, only the labor cost will be slightly higher. If a car that is not too old experiences a sense of looseness, it is usually caused by a problem somewhere. A thorough inspection and maintenance can easily solve the problem. Some cheap cars have a slightly loose and bulky chassis since the beginning of a new car. This is due to the design and materials used, and cannot be changed, so there is no need for maintenance. So whether the chassis divergence is a fault depends on comparing the same vehicle with its previous usage, and cannot be compared between different vehicle models.
From: WONDEE Autoparts 2023-8-8