Should Both Shock Absorbers Be Replaced If One Is Damaged?

[McPenelope]

When a car's shock absorber is damaged, it is necessary to replace a pair. Replacing only one can affect the vehicle's handling and balance, as shock absorbers are crucial for both handling and comfort. Shock absorbers are wear-prone components that require periodic replacement. Over time, they can become damaged. A car's shock absorber consists of a spring and a damping cylinder. The spring is the elastic element, while the damping cylinder functions to limit the number of spring oscillations. If there is only a spring without a damping cylinder, the car body may oscillate excessively when driving over rough terrain, negatively impacting comfort and handling. Methods to check if a shock absorber is damaged: 1. Drive the car on a rough road for 10 km, then stop and touch the shock absorber housing. If it is not warm, it indicates no internal resistance, meaning the shock absorber is not working. Adding appropriate lubricant and retesting may help—if the housing becomes warm, it suggests insufficient oil inside, which should be replenished. Otherwise, the shock absorber may be faulty. 2. Press down firmly on the bumper and release. If the car bounces 2-3 times, the shock absorber is functioning well. 3. If the car vibrates severely during gentle driving followed by sudden braking, the shock absorber may be problematic. 4. Remove the shock absorber, stand it upright, and clamp the lower connecting ring in a vise. Pull and push the shock absorber rod several times—there should be stable resistance. The resistance when pulling up should be greater than when pushing down. If resistance is unstable or absent, the shock absorber may lack oil or have damaged internal valves, requiring repair or part replacement. After confirming a faulty or ineffective shock absorber, check for oil leaks or signs of past leaks. Damaged oil seal gaskets, sealing washers, or loose oil reservoir cap nuts may indicate seal failure, necessitating replacement. If leaks persist, inspect the piston-cylinder clearance for excessive wear, check for bending in the piston rod, and examine the piston rod and cylinder surfaces for scratches or scoring. If no oil leaks are found, inspect the shock absorber's connecting pins, rods, holes, rubber bushings, and other components for damage, detachment, or cracks. If these appear normal, further disassemble the shock absorber to check the piston-cylinder clearance, cylinder scoring, valve seal integrity, and the condition of the extension spring—repair or replace parts as needed. In practice, shock absorbers may produce noise due to collisions with leaf springs, the frame, or axle, damaged or missing rubber pads, deformed dust covers, or insufficient oil. Identify the cause and repair accordingly. After inspection and repair, test the shock absorber on a specialized bench. At a resistance frequency of 100±1 mm, the extension and compression resistance should meet specifications, indicating normal function.

[Freya]

As someone with extensive experience in car repairs, I can tell you that if one shock absorber is broken, it's advisable to replace both at the same time. This is mainly because the suspension system needs to maintain left-right balance. Replacing only one can lead to unstable driving, especially during sharp turns or on bumpy roads, causing the vehicle to lean to one side, which affects handling and safety. Additionally, the old shock absorber is already worn out and may have a much shorter lifespan than the new one. If you only replace one, the other might fail soon after, leading to additional costs and time for repairs. I've seen many car owners try to save money by replacing just one side, only to end up with uneven tire wear or even damage to other chassis components, costing them more in the long run. Overall, replacing both shock absorbers at once can extend the vehicle's lifespan, improve driving comfort, and be more economical, avoiding the hassle of repeated repairs. Specifically, check if all the shock absorbers show signs of aging—if they do, replacing them in pairs is the safest approach.