What Causes Shifting Shudder in Automatic Transmissions?
3 Answers
Because the transmission gear oil is relatively viscous and dense, the transmission components receive the engine's power more noticeably, causing the vehicle to shake significantly. Below is relevant information about automatic transmission shifting: 1. When waiting at a red light for an extended period: If you're waiting at an intersection for a prolonged red light, it's advisable to shift to N (Neutral) and engage the handbrake. Keeping your foot on the brake for too long can cause the transmission fluid temperature to rise excessively. 2. Avoid frequent use of S (Sport) mode: When shifting into S mode, the vehicle can change gears freely. While this feature is convenient, frequent use of S mode can severely impact the transmission. Typically, S mode should only be used during high-speed overtaking.
As a mechanic, I often deal with such issues. The most common cause of jerking during automatic transmission gear shifts is a problem with the transmission fluid, such as low fluid levels or aged, contaminated fluid, which affects hydraulic pressure transmission and leads to rough shifting. Another frequent factor is worn or loose engine mounts or transmission mounts, which support critical components during vehicle operation—once they fail, vibrations become noticeable during gear shifts. Occasionally, faults in the drivetrain, such as issues with the half-shafts or torque converter, can also cause jerking. For electronically controlled vehicles, a malfunction in the computer module may also lead to problems. If jerking occurs, it’s crucial to inspect and repair it early—don’t wait until the shaking becomes severe enough to affect driving stability. Visiting a professional repair shop to check the transmission fluid and mounts is a key step.
From a safety perspective, I consider this issue quite important. Gear shift vibration not only affects driving comfort but can also make the vehicle unstable during lane changes or acceleration, potentially leading to accidents. Possible causes include wear and tear of internal transmission components, such as aging clutch plates slipping, or blocked oil passages affecting fluid dynamics. Personally, I recommend stopping the vehicle if frequent vibrations are observed and avoiding long-distance driving under such conditions. First, check simple components like whether a fuse has blown, then have a technician use a diagnostic tool for testing. Timely intervention can prevent more severe damage and ensure peace of mind for every trip.
