What causes shaking when braking in D gear?

[StJaxson]

Reasons for shaking when braking in D gear: If it's a slight shake, it's normal. If the shaking is severe, it might be caused by a damaged engine mount. Engine mounts, usually made of rubber, connect the engine to the frame and help absorb engine vibrations. Here's some additional information: 1. P——Parking, the parking gear, also the starting position. When you park and don't need to move, the wheels are mechanically locked to prevent rolling. 2. R——Reverse, the reverse gear used for backing up. N——Neutral, the neutral gear. Use this gear when temporarily stopping (e.g., at a red light). Note: This gear means neutral; to prevent the vehicle from rolling on a slope, always keep the brake pedal pressed. 3. D——Drive, the forward gear, also known as the driving gear. Use this gear when moving forward. 4. L——Low, the low-speed gear. When going downhill or on long descents, using this gear limits the car to the lowest gear (equivalent to first gear in a manual transmission), allowing engine braking so the driver doesn't have to press the brake pedal for extended periods, which could overheat the brake pads and cause danger. 5. S——Sport, indicating sport mode. When engaged, the gear can switch freely, but shifting is delayed to keep the engine at high RPMs for better performance. This mode increases fuel consumption.

[StGabriella]

I used to frequently experience shaking when shifting to D gear and stepping on the brake, especially in older cars, where the entire steering wheel would tremble. From what I understand, this is mostly due to engine mounts. Those rubber pads harden and deteriorate over time, losing their cushioning effect, so the engine's vibrations are directly transmitted to the car body. Another issue could be unstable engine idling. If the intake system or spark plugs are carbon-fouled, it can lead to incomplete combustion, causing uneven engine operation. Additionally, the torque converter is responsible for power transmission in D gear. If it's worn out or the transmission fluid isn’t clean enough, it can also cause vibration transmission. I recommend starting with simple checks, like popping the hood to inspect the engine mounts for cracks or softening, and cleaning the throttle body. If the problem persists, it’s best to take the car to a repair shop for a professional diagnosis. Continuing to drive with the issue could damage more components, affect driving safety, and even increase fuel consumption.

[Ruby]

I've been driving an automatic transmission car for several years and noticed that it shakes noticeably when stopped at a red light in D gear with the brake pedal pressed, feeling like the whole car is vibrating slightly. After researching, I learned this usually isn't due to the brake discs themselves, but rather an issue with the engine idle control – like a clogged air filter or dirty fuel injectors causing uneven engine operation. Another common factor is reduced efficiency in the torque converter when transmitting power in D gear, possibly from aging internal components or needing transmission fluid replacement. Engine mounts shouldn't be overlooked either, as those cushioning parts harden and fail over time. For this problem, I'd suggest first cleaning the throttle body and replacing the air filter to see if idle improves. If no change, then inspect the mounts or transmission system. Addressing it early can prevent costlier repairs and make starts smoother.

[LeJessica]

I noticed the car shakes when parked in D gear with the brake pressed, most likely due to aging engine mounts. When those rubber supports lose elasticity, engine vibrations transfer to the body. Additionally, carbon buildup in the engine or spark plug issues can cause unstable idling, introducing extra vibration to the system. I recommend visiting a repair shop for a quick diagnosis first—check the engine RPM or inspect the mount condition. Don't delay too long, otherwise the shaking may worsen the damage.