What Causes Excessive Shaking When Starting a Manual Transmission Car?

[McNathan]

The reasons for excessive shaking when starting a manual transmission car include: 1. Insufficient engine power; 2. Loose connections between the transmission and chassis, or uneven engagement of the clutch pressure plate and clutch friction disc; 3. Dirty throttle body or excessive carbon buildup on the fuel injectors. If the vehicle shakes when the clutch is released to the semi-engaged position, this is a normal phenomenon known as the car's creeping effect. During the process of starting from a standstill and slowly releasing the clutch pedal, if the vehicle shakes, this is due to irregular wear of the clutch assembly components—namely the flywheel, clutch disc, and pressure plate—causing one or more of these parts to become misaligned. During engagement, the clutch disc cannot smoothly engage but instead engages and disengages intermittently. This results in the engine power being transmitted initially and then suddenly slipping, causing the vehicle to exhibit a jerking sensation. Replacing the damaged components in the clutch assembly can resolve this issue.