Symptoms
- Vehicle rolls slightly or fully when shifter is in park
- Shifter may feel slightly loose or different than usual
- Sometimes intermittent, holding on flat ground but not inclines
- May be accompanied by other shifting issues
Likely causes
- CommonWorn parking pawl teethRepeated engagement wears the teeth that lock the output shaft, eventually letting it slip.
- PossibleBroken pawl spring or actuator rodThe mechanism that pushes the pawl into place can break, preventing full engagement.
- PossibleShift linkage misalignmentIf the linkage doesn't fully move the internal selector to true park, the pawl may not engage properly even though the shifter looks correct.
- Less commonInternal transmission wearGeneral wear inside an aging transmission can affect this mechanism along with others.
What to do
- Use the parking brake every time you park, on any surface, until this is resolved.
- Test on level ground first to see if the car holds, then very cautiously on a slight incline with the parking brake ready as backup.
- Do not leave the vehicle unattended on an incline without the parking brake set, regardless of what the shifter shows.
- Have a transmission specialist inspect the pawl mechanism and shift linkage.
- Repair or replace the worn pawl, spring, or linkage component identified.
- Confirm the fix by testing on an incline with the parking brake off (safely, with someone present) before relying on park alone again.
- Treat this as a priority repair rather than something to defer.
When to call a pro
See a transmission shop promptly, since this affects the vehicle's ability to stay safely parked.
Safety
Use caution
Always use the parking brake as backup until this is repaired; a car that doesn't hold in park can roll and cause injury or damage.