What Causes Severe Shaking When Shifting Gears in an Automatic Transmission?
2 Answers
Severe shaking of the vehicle body when shifting gears in an automatic transmission is due to the gear oil in the transmission being too viscous and dense, causing the drivetrain to receive the engine's power more noticeably, thus resulting in a noticeable shake of the car. This situation requires prompt attention. Possible reasons for the gear oil becoming viscous: The gear oil may have been contaminated with various impurities and metal shavings inside the gearbox during operation; some of the light oil components in the gear oil may have naturally evaporated during use; or the properties of the gear oil may have changed due to deterioration after its expiration date. Corresponding solutions: If the issue is contamination with impurities, timely cleaning is sufficient; if it's due to the natural evaporation of light oil, timely addition of light oil is needed; if the gear oil has expired, it should be replaced promptly. Key points for shifting gears in an automatic transmission: When shifting between gears other than D and S, first press the brake, then move the gear lever to the desired gear, and finally release the brake to complete the gear shift.
I've been driving for over twenty years, and severe shaking during automatic transmission gear shifts is quite common. The main issue is usually with the transmission fluid: insufficient or degraded fluid leads to poor lubrication, making gear shifts rough; a clogged filter can also affect fluid pressure, causing severe shaking. Another possibility is a worn-out torque converter—when it deteriorates, the clutch plates don’t engage smoothly, especially noticeable during low-speed gear shifts. Engine-related issues, like ignition system failures or worn spark plugs, can also cause uneven engine performance, which naturally affects the transmission. Last month, my car shook violently during a highway gear shift, and a check revealed low fluid levels—topping it up fixed the issue. I recommend fellow drivers first check the fluid level themselves; pop the hood and inspect. If that doesn’t help, visit a professional shop for a thorough diagnosis—don’t wait until repair costs double. Regular maintenance is key to avoiding major issues, especially for older cars.