What are the causes of transmission jerking?
2 Answers
Transmission jerking is caused by: excessively high transmission oil temperature, stubborn dirt and impurities inside the transmission forming blockages in the valve body, hindering smooth movement of solenoid valves and preventing sequential regulation of oil pressure, leading to jerking, impact, and slippage faults. The sensation of transmission jerking stems from the inertial impact generated by moving components within the engine, and can be attributed to poor shifting quality and malfunctions. The functions of a transmission are: 1. To alter the transmission ratio, meeting the traction requirements under different driving conditions and enabling the engine to operate under favorable circumstances; 2. To enable the vehicle to move in reverse; 3. To interrupt power transmission, allowing the engine to start and idle, the vehicle to shift gears or park, and cutting off power to the drive wheels; 4. To engage neutral gear, stopping power output from the transmission when the clutch is engaged.
I've driven a taxi for over a decade and seen plenty of transmission jerking issues. The most common cause is deteriorated transmission fluid - it's like blood, when dirty it flows poorly causing rough shifting. Then there's solenoid valve failure, which means shift commands aren't properly transmitted. The worst is clutch wear - I once saw a guy who did launch starts daily and wore out his clutch discs in just 20,000 km. Another issue is TCU program errors causing abnormal shift logic. Oh, and I forgot to mention low fluid level can also cause jerking - last month the shop handled a case caused by fluid leaks. Bottom line: transmissions are delicate, never slack on maintenance checks.
