What causes the jerk when shifting from CVTD to N?
3 Answers
Damaged solenoid valves are a major cause of jerking. The distinction is simple: occasional jerking occurs without a pattern, while consistent jerking happens at a certain RPM or when shifting between specific gears (e.g., from 2nd to 3rd). The reason for jerking at fixed speeds is: sludge in the transmission fluid circulating and clogging the oil passages in the valve body. Over time, this can lead to a series of transmission issues such as overheating, harsh shifting, and slipping. More reasons are as follows: 1. Presence of contaminants: Transmission jerking or harsh shifting is often not due to internal valve body damage but rather stubborn dirt and contaminants inside, especially when they accumulate in the valve body, blocking oil passages and preventing effective oil pressure regulation, leading to jerking, harsh shifting, and slipping. The traditional solution is to replace the transmission fluid. 2. Insufficient air intake: The engine's air intake system—engines require not only fuel but also air. If components like the air filter or throttle body are clogged or malfunctioning, reducing air intake, it can result in sluggish acceleration and jerking. The ignition system should not be overlooked either; if spark plugs misfire, leak, or fail to atomize properly, it can also affect engine acceleration.
After working in the repair shop for a long time, I often notice that vehicles experience jerking when shifting from D to N gear. The main cause is a faulty torque converter clutch, which creates an impact sensation when the lock-up release is not smooth. Uneven oil pressure can also worsen the problem. Sometimes, it's due to aged or contaminated transmission fluid, which reduces lubrication and causes excessive gear friction, or sluggish software responses from the control module. I recommend owners check the transmission fluid level and color—if it appears black or has a burnt smell, replace it promptly. If the issue persists after a fluid change, don’t delay—visit a professional shop to inspect the solenoids or sensors. Ignoring this long-term could damage the entire drivetrain and compromise driving safety. This issue is particularly common in older models, often occurring after frequent gear shifts.
Having driven for decades, I've noticed that the sudden jerk when shifting from D to N in an automatic transmission is quite annoying, mainly due to insufficient oil or deteriorated oil with high viscosity causing inadequate lubrication and component sticking. In older cars, gear wear and loose torque converters can also be contributing factors. A simple fix is to first check the transmission dipstick to ensure the oil level is between the marks and the color is clear. If you're not mechanically inclined, don't tinker blindly—drive to a repair shop for diagnosis. In most cases, changing the oil can alleviate the issue; otherwise, it may lead to more severe problems like acceleration slippage. Remember to maintain regular servicing, especially in hot weather when oil oxidizes easily—don't skimp on these small expenses.
