Why does the car shake in D gear when braking but not in N gear?
3 Answers
D gear shifts to N gear shaking is caused by a dirty throttle, spark plug failure, or brake disc failure. Dirty throttle: When carbon deposits or other pollutants adhere to the throttle, it disrupts the balance between the amount of air the engine inhales and the fuel injected by the fuel injector, leading to insufficient fuel during engine operation, resulting in body shaking. Cleaning the throttle can solve this issue. Spark plug failure: When the vehicle shakes violently, it is often due to a problem with the spark plugs. It is necessary to check if any spark plug in a cylinder is damaged. Replacing the spark plugs can resolve this issue. Brake pad failure: When the brake pads are heavily worn, you may feel a decrease in braking effectiveness and body shaking when braking, along with abnormal noises from the wheels. Replacing the brake pads can solve this problem. Shifting techniques: Shift quickly, control the starting gear, keep your eyes forward while shifting, shift sequentially, and shift smoothly. Shifting precautions: Do not look down during shifting, always pay attention to road conditions, press the clutch pedal fully when shifting, do not skip gears, and do not stay in first gear all the time.
I've been driving for almost 20 years, and this issue is quite common. When you're in D gear with the brake pedal pressed, the engine remains connected to the transmission system. It's like a stubborn guy trying hard to push the wheels forward, but the brakes insist on holding it back. These two forces are in a tug-of-war, causing the car to shake, as if it's in a standstill tug-of-war. In N gear, the transmission is completely disconnected, and the engine spins freely with no opponent to fight, naturally staying quiet and steady. This shaking can sometimes be a sign of an aging car. Worn engine mounts or torque converter wear can make the situation worse. I recommend checking the rubber mounts—they're supposed to absorb vibrations, but if they're damaged, they can't handle the pressure. Regular maintenance of transmission fluid and components can prevent this. Don't wait until the shaking gets severe to fix it. When changing tires, take the opportunity to inspect related parts—it saves hassle and money, and your car can last longer.
When working as an apprentice at an auto repair shop, I often encountered similar cases. Shaking while parked in D gear is mostly caused by deformed engine mounts or torque converter issues. The mounts act like shock absorbers for the car body, normally absorbing engine vibrations. But in D gear, the torque converter maintains pressure and tries to drive the wheels, causing cabin vibrations when opposing the braking resistance. Once shifted to N gear, the transmission is completely relieved of the load, and the torque converter has no load, thus no conflict. If the shaking is severe, it might be due to loose mount bolts or dirty transmission fluid—replacing them promptly solves the issue. Don’t overlook this; even minor shaking can shorten the lifespan of chassis components. I’ve helped customers deal with this several times—low-cost maintenance prevents major repairs.
