What Causes Slight Shaking When Shifting Gears in a Car?
2 Answers
Reasons for car shaking when shifting gears are as follows: Cold Start Shaking: Starting with cold starts, the main reason for body shaking during a cold start is insufficient fuel combustion, leading to inadequate power output. Low ignition energy requires more throttle input to meet power demands, especially when fuel and lubricant temperatures are low. Over time, the electrode gap of spark plugs gradually widens, reducing ignition energy and impairing fuel atomization, which results in body shaking. Additionally, aging ignition coils, high-voltage wires of spark plugs, or electrical leakage can also decrease ignition energy. Suspension System Issues: Body shaking is also related to aging suspension systems. The suspension primarily filters out engine vibrations during operation. If the suspension malfunctions, these vibrations directly transmit to the steering wheel and cabin, affecting driving. When the engine is idling, turning on electrical systems inside the car can easily cause shaking. The engine load increases due to the activation of electrical systems, causing idle speed to drop. To compensate for the shaking caused by idle speed drop, the engine automatically raises the rpm slightly. Therefore, when electrical systems, especially the air conditioning, are turned on, the engine often shakes. This shaking is likely due to aging suspension components and requires timely replacement. Tire Problems: For tires, whenever new tires or rims are installed, wheel balancing is necessary. Otherwise, uneven weight distribution can cause the steering wheel to shake. If uneven weight distribution is detected, lead weights must be added inside the rims to balance the weight on both sides. Whether standard steel rims or lightweight aluminum rims, they can deform or crack under certain external forces. Rim deformation leads to shaking while driving, uneven rim weight distribution also causes shaking, and incorrect rim angles can similarly result in shaking during driving.
I've experienced gear shift vibrations several times while driving, which seems quite common. One possible reason is clutch wear, especially in older small cars. After prolonged use, worn-out parts can make gear shifting less smooth, leading to vibrations. Another issue could be with the spark plugs; if the ignition system is dirty or faulty, engine instability can transmit vibrations to the gear shift. Additionally, insufficient or dirty transmission fluid can reduce lubrication effectiveness, causing friction and vibrations during gear shifting. Also, aging engine mounts, if cracked, can cause the entire engine to shake, making vibrations noticeable during gear shifts. Warming up the engine for a few minutes before driving can reduce cold-start vibrations. Regularly checking fluid levels and spark plugs, and replacing them yourself if needed, isn't expensive and can save costly repairs at the shop. By the way, for manual transmissions, check if the shifting technique is too abrupt; gently pressing the clutch and shifting slowly might help.
