What Causes the Inability to Shift Gears After Starting the Car?
2 Answers
There are several reasons why a car may not shift gears after starting, including incomplete clutch disengagement, deformation of the gear linkage mechanism, and gear lock. Here are detailed explanations: 1. Reasons: Shift into gear and start the engine while pressing the clutch to see if the car moves. Alternatively, start the engine and shift into a high gear to listen for any grinding sounds. If there are grinding sounds, it indicates incomplete clutch disengagement. Deformation of the gear linkage mechanism can prevent shifting. It could also be due to gear lock or not fully engaging the brake when parking, leading to gear braking instead of brake braking. If the entire vehicle cannot power on, the automatic transmission may enter self-protection mode, preventing gear shifting. In such cases, gear unlocking can be performed by pressing the black button above the transmission's P (Park) position. 2. Working Principle: A car transmission is essentially a gearbox containing multiple gears. The driving gear (connected to the engine via the clutch) receives power from the engine and drives the driven gear (connected to the wheels via the final drive and drive shaft), thereby turning the wheels. Each gear has a pair of driving and driven gears, and shifting into a specific gear engages that pair to transmit power.
I've been driving for twenty years, and this issue is quite common. After starting the engine, you press the clutch and try to shift gears, but the gear lever feels like it's welded in place? Most likely, the clutch isn't fully disengaging. It could be that the clutch disc is worn too thin and won't separate even when fully pressed, or there's a leak in the hydraulic system—brake fluid might be dripping from the slave cylinder. I remember one time my car had stiff shifting; when I took it to the shop, they found the rubber boot on the shift cable had cracked, letting in sand particles. Automatic transmissions are trickier—if the transmission fluid is dark and sticky like syrup, the valve body inside can easily get clogged. I recommend checking the brake fluid reservoir level and topping it off if it's low. If that doesn’t help, shut off the engine immediately and call for a tow truck. Forcing it into gear could damage the synchronizer gears.
