What Causes the Jerk When Shifting from First to Second Gear?
4 Answers
The main reasons for the jerking sensation when shifting from first to second gear are improper coordination between the clutch and throttle, and mismatched engine speed and vehicle speed during gear shifting. In actual driving, first gear is often used as the starting and acceleration gear for quicker starts. When shifting to second gear, the vehicle speed is around 20km/h, and both the vehicle speed and engine speed are relatively high. Additionally, if the driver presses the throttle too quickly after releasing the clutch pedal to further increase speed, the engine speed drops significantly, while the increased throttle input raises torque output, resulting in a jerking sensation. For smoother shifting, it's best to keep the vehicle speed below 10km/h when fully releasing the clutch pedal and shifting to second gear. If you want to achieve a quick start and acceleration, pressing the clutch pedal while simultaneously pressing the throttle when the speed reaches 20km/h can prevent a significant drop in engine speed due to clutch release. Shifting to second gear at this point allows for smoother clutch engagement and reduces jerking, but this method may cause some damage to the clutch and is not recommended for long-term use.
After driving a manual transmission car for several years, the most common cause of jerking when shifting from first to second gear is clutch operation issues. If the clutch is released too quickly or too slowly during shifting, causing a mismatch between engine speed and gear position, it will result in jerking. For example, if the accelerator is pressed too deeply and you upshift before the RPM drops sufficiently, the engine will be pulled and shake. It could also be due to worn clutch discs that can't grip properly and slip during shifting. Another key factor is transmission fluid—if the oil is too thick or insufficient, the synchronizers won't work smoothly, making shifts feel harsh. I recommend practicing coordination between the accelerator and clutch while driving, developing the habit of easing off the throttle before depressing the clutch to reduce jerking. Occasional occurrences might be normal, but frequent jerking warrants checking the transmission fluid or clutch discs—don't delay, as it can damage the car and waste fuel. In cold weather, the oil thickens, making jerking more likely; warming up the car for a few minutes before driving can help. In short, jerking during shifting is usually due to either driver technique or vehicle issues—it's best to have a professional mechanic inspect it for peace of mind.
As a daily commuter, I've experienced second gear jerking several times, often due to simple mistakes. The main issue is inconsistent shifting movements—when shifting from first to second, my hand moves too fast while the clutch pedal isn't fully depressed, causing poor RPM synchronization. Additionally, low engine RPM is problematic, like driving off immediately in first gear when the engine is cold before the RPM builds up, leading to jerky upshifts. If the car is old with a worn-out transmission synchronizer, it can also cause jerking, feeling like gears are grinding harshly. Another minor detail is improper throttle control—not releasing the throttle timely before shifting results in uneven power delivery. I've tried adjusting my driving habits, such as waiting for the RPM to stabilize around 2,000 before upshifting, and checking transmission fluid levels by popping the hood to inspect the dipstick. For severe cases, avoid forcing it—have a mechanic scan for trouble codes to prevent internal transmission wear. Developing regular maintenance habits, like changing fluids every 30,000 km, can prevent many minor issues.
After driving for many years, I believe that the jerkiness when shifting from first to second gear is mostly due to transmission oil issues. The oil may have aged or the level is low, leading to insufficient lubrication and poor synchronizer performance, causing hesitation during gear changes. In daily driving, excessively high oil temperature or water contamination can also cause this. A minor repair involving an oil change might restore smooth operation. I recommend car owners regularly check the oil level and color, and replace it immediately if it turns black or cloudy to avoid costly transmission repairs.
