What is the reason for the impact sound when accelerating with a dual-clutch transmission?

[PaulLynn]

The reason for the impact sound when accelerating with a dual-clutch transmission is that the clutch is not fully depressed. Introduction to dual-clutch transmissions: An automotive dual-clutch transmission (DCT) is a type of transmission that has two clutches—one controlling the odd-numbered gears and the other controlling the even-numbered gears. A dual-clutch transmission combines the characteristics of both manual and automatic transmissions, offering the flexibility of a manual transmission and the comfort of an automatic transmission while providing uninterrupted power output. It acts as a switch for power transmission between the engine and the transmission. The function of a dual-clutch transmission: The primary function of a dual-clutch transmission is to ensure smooth vehicle starts, reduce the impact load on the transmission gears during gear shifts, and prevent overloading of the drivetrain. When using a dual-clutch transmission, it is advisable to frequently engage the manual mode. This is because the dual-clutch system has a memory programming feature—regular use of the manual mode allows the transmission to develop a memory effect and operate based on this memorized pattern. This helps reduce shift frequency and lowers the probability of faults occurring.

[MartinDella]

I've been driving for over a decade, and it's quite common to hear a clunking sound when accelerating with a dual-clutch transmission. This is usually caused by worn clutch plates or excessive gear clearance. The design of dual-clutch transmissions relies on rapid switching between two clutches, but if you frequently drive in stop-and-go city traffic or drive aggressively, the clutch discs can wear down and thin out, resulting in a clicking or clunking noise when accelerating. Additionally, insufficient or degraded gearbox oil can lead to inadequate lubrication of components, causing impact sounds during operation. I remember my old car had this issue before, and it turned out to be delayed signals from the control module, causing inconsistent power delivery. These problems can worsen transmission damage and increase repair costs. So, whenever I encounter this situation, I take it to a professional repair shop immediately—don’t wait until a minor issue becomes a major repair. Regular maintenance, like changing transmission oil periodically, is a cost-saving measure.

[LeLaila]

As a car enthusiast, I've noticed that the clunking sound when accelerating with a dual-clutch transmission is commonly caused by clutch system failures, especially issues in the hydraulic control components. Dual-clutch systems rely on hydraulic pressure to engage the clutch plates - if the seals age and leak or there's insufficient pressure, you'll feel impact sounds during acceleration, somewhat like metal clashing. Driving habits also play a role; sudden acceleration or overloading conditions where load changes abruptly can more easily trigger this issue. I remember when I upgraded my engine's horsepower, the sound appeared, and later diagnostics revealed it was due to improper TCU (Transmission Control Unit) calibration causing signal transmission disorder. Insufficient lubrication is another critical factor - prolonged oil neglect accelerates wear. I recommend using specialized diagnostic equipment for inspection and avoiding cheap non-professional shops, as improper handling might require complete transmission replacement. For daily driving, maintaining smooth acceleration can help minimize such occurrences.

[OHeidi]

I place great emphasis on driving safety, and the clunking sound from the dual-clutch transmission during acceleration may indicate potential risks that should not be ignored. Possible causes include severe wear of the clutch plates or hydraulic system failure, which can lead to gear desynchronization during acceleration, resulting in metallic clunking noises. If left unaddressed, it may cause transmission lock-up or even breakdown, especially dangerous on highways. Whenever I encounter abnormal sounds, I immediately reduce speed, pull over to inspect, ensuring safety comes first. For prevention, regularly check the transmission fluid level and quality, replacing it every 20,000-30,000 kilometers. It's best to visit a repair shop for diagnosis as early as possible. Common repairs include adjusting clutch clearance or replacing worn components, which are not costly. In daily driving, avoid sudden throttle inputs and operate gently to prolong lifespan.