* Shift Cable Adjustment/Wear: The most likely cause is a worn or improperly adjusted shift cable. Over time, the cable can stretch, fray, or become kinked, preventing smooth shifting. This is especially true for the park position, which often requires more force than other gears.
* Shift Linkage: Problems with the linkage connecting the shifter to the transmission can also cause sticking. This could involve bent or broken components, worn bushings, or binding points.
* Internal Transmission Issues: While less likely to cause *only* the park issue, problems within the transmission itself (like low fluid, internal wear, or a failing shift solenoid) can sometimes create resistance that makes it difficult to select park. This is more likely if you are experiencing other transmission problems.
* Park Pawl: The park pawl is a mechanism inside the transmission that locks the output shaft in place when the car is in park. A worn or damaged park pawl can make it difficult or impossible to engage park.
* Broken or Damaged Shift Interlock: This is a safety mechanism that prevents the car from being started unless it's in park. A malfunction in this system can interfere with the shifter's movement.
In short: It's almost certainly a mechanical problem related to the shifter cable, linkage, or a component within the transmission itself preventing the park mechanism from engaging. Do not attempt to force the shifter. Forcing it could damage the components further.
What to do: This is a safety issue. Driving a car that won't reliably go into park is dangerous. You should have a qualified mechanic diagnose and repair the problem immediately. Attempting a DIY fix without experience can be risky and may lead to more extensive damage.
