What Causes Severe Shaking When Shifting to R Gear in an Automatic Transmission?
2 Answers
The reasons for severe shaking when shifting to R gear in an automatic transmission are: 1. Low idle speed; 2. Dirty throttle body; 3. Dirty fuel injectors; 4. Severe engine carbon buildup; 5. Poor spark plug performance. It is normal for automatic transmission vehicles to experience slight shaking when shifting gears, as the clutch differential is engaged and the engine generates torque. However, it is important to note that the vehicle must be completely stopped before shifting gears. When reversing, the direction of power transmission needs to change. Shifting gears without stopping the vehicle can cause noise in the transmission and may even severely damage it. An automatic transmission eliminates the need for the driver to manually shift gears, as the vehicle automatically selects the appropriate gear based on driving speed and traffic conditions. Typically, automatic transmission vehicles have six gear positions, arranged from top to bottom as: P, R, N, D, S, L.
Last time my car shook violently when shifting into reverse gear. After a mechanic's inspection, the main cause was likely broken engine mounts—these components stabilize the engine, and once they age or crack, the load shift during gear changes can easily cause vibrations. Another possibility is a faulty transmission torque converter, which bears extra pressure in reverse gear; insufficient fluid or worn parts can lead to shaking. Additionally, loose drive shafts or half-shafts may trigger vibrations, as in my case where irregular checks caused unbalanced, loosened parts. For safety, I recommend first inspecting engine mounts for cracks, testing stability in neutral before shifting, as severe vibrations risk damaging other components. Don’t delay such issues—visit a professional shop promptly to prevent high-speed hazards. Regular maintenance helps early prevention.
